* [PATCH v28 07/25] LSM: Use lsmblob in security_secctx_to_secid
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 08/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
` (6 subsequent siblings)
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, netdev, netfilter-devel
Change the security_secctx_to_secid interface to use a lsmblob
structure in place of the single u32 secid in support of
module stacking. Change its callers to do the same.
The security module hook is unchanged, still passing back a secid.
The infrastructure passes the correct entry from the lsmblob.
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
To: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/linux/security.h | 26 ++++++++++++++++++--
kernel/cred.c | 4 +---
net/netfilter/nft_meta.c | 10 ++++----
net/netfilter/xt_SECMARK.c | 7 +++++-
net/netlabel/netlabel_unlabeled.c | 23 +++++++++++-------
security/security.c | 40 ++++++++++++++++++++++++++-----
6 files changed, 85 insertions(+), 25 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 332df8a1cd4d..986a8f4bcd54 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -196,6 +196,27 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
extern int lsm_name_to_slot(char *name);
extern const char *lsm_slot_to_name(int slot);
+/**
+ * lsmblob_value - find the first non-zero value in an lsmblob structure.
+ * @blob: Pointer to the data
+ *
+ * This needs to be used with extreme caution, as the cases where
+ * it is appropriate are rare.
+ *
+ * Return the first secid value set in the lsmblob.
+ * There should only be one.
+ */
+static inline u32 lsmblob_value(const struct lsmblob *blob)
+{
+ int i;
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++)
+ if (blob->secid[i])
+ return blob->secid[i];
+
+ return 0;
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
@@ -527,7 +548,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+ struct lsmblob *blob);
void security_release_secctx(char *secdata, u32 seclen);
void security_inode_invalidate_secctx(struct inode *inode);
int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
@@ -1382,7 +1404,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
static inline int security_secctx_to_secid(const char *secdata,
u32 seclen,
- u32 *secid)
+ struct lsmblob *blob)
{
return -EOPNOTSUPP;
}
diff --git a/kernel/cred.c b/kernel/cred.c
index ea36ec6e1ad8..38b00a1390f4 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -798,14 +798,12 @@ EXPORT_SYMBOL(set_security_override);
int set_security_override_from_ctx(struct cred *new, const char *secctx)
{
struct lsmblob blob;
- u32 secid;
int ret;
- ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
+ ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
if (ret < 0)
return ret;
- lsmblob_init(&blob, secid);
return set_security_override(new, &blob);
}
EXPORT_SYMBOL(set_security_override_from_ctx);
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index a7e01e9952f1..f9448e81798e 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -809,21 +809,21 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
static int nft_secmark_compute_secid(struct nft_secmark *priv)
{
- u32 tmp_secid = 0;
+ struct lsmblob blob;
int err;
- err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
+ err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
if (err)
return err;
- if (!tmp_secid)
+ if (!lsmblob_is_set(&blob))
return -ENOENT;
- err = security_secmark_relabel_packet(tmp_secid);
+ err = security_secmark_relabel_packet(lsmblob_value(&blob));
if (err)
return err;
- priv->secid = tmp_secid;
+ priv->secid = lsmblob_value(&blob);
return 0;
}
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index 498a0bf6f044..87ca3a537d1c 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -42,13 +42,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_secmark_target_info_v1 *info)
static int checkentry_lsm(struct xt_secmark_target_info_v1 *info)
{
+ struct lsmblob blob;
int err;
info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
info->secid = 0;
err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
- &info->secid);
+ &blob);
if (err) {
if (err == -EINVAL)
pr_info_ratelimited("invalid security context \'%s\'\n",
@@ -56,6 +57,10 @@ static int checkentry_lsm(struct xt_secmark_target_info_v1 *info)
return err;
}
+ /* xt_secmark_target_info can't be changed to use lsmblobs because
+ * it is exposed as an API. Use lsmblob_value() to get the one
+ * value that got set by security_secctx_to_secid(). */
+ info->secid = lsmblob_value(&blob);
if (!info->secid) {
pr_info_ratelimited("unable to map security context \'%s\'\n",
info->secctx);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2483df0bbd7c..c29a8d7a7070 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -882,7 +882,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
void *addr;
void *mask;
u32 addr_len;
- u32 secid;
+ struct lsmblob blob;
struct netlbl_audit audit_info;
/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -906,13 +906,18 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
ret_val = security_secctx_to_secid(
nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
- &secid);
+ &blob);
if (ret_val != 0)
return ret_val;
+ /* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
+ * instead of a u32 later in this patch set. security_secctx_to_secid()
+ * will only be setting one entry in the lsmblob struct, so it is
+ * safe to use lsmblob_value() to get that one value. */
+
return netlbl_unlhsh_add(&init_net,
- dev_name, addr, mask, addr_len, secid,
- &audit_info);
+ dev_name, addr, mask, addr_len,
+ lsmblob_value(&blob), &audit_info);
}
/**
@@ -933,7 +938,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
void *addr;
void *mask;
u32 addr_len;
- u32 secid;
+ struct lsmblob blob;
struct netlbl_audit audit_info;
/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -955,13 +960,15 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
ret_val = security_secctx_to_secid(
nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
- &secid);
+ &blob);
if (ret_val != 0)
return ret_val;
+ /* security_secctx_to_secid() will only put one secid into the lsmblob
+ * so it's safe to use lsmblob_value() to get the secid. */
return netlbl_unlhsh_add(&init_net,
- NULL, addr, mask, addr_len, secid,
- &audit_info);
+ NULL, addr, mask, addr_len,
+ lsmblob_value(&blob), &audit_info);
}
/**
diff --git a/security/security.c b/security/security.c
index 69474918be8b..1621a28bf9c4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2193,10 +2193,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
}
EXPORT_SYMBOL(security_secid_to_secctx);
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+ struct lsmblob *blob)
{
- *secid = 0;
- return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
+ struct security_hook_list *hp;
+ int rc;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.secctx_to_secid(secdata, seclen,
+ &blob->secid[hp->lsmid->slot]);
+ if (rc != 0)
+ return rc;
+ }
+ return 0;
}
EXPORT_SYMBOL(security_secctx_to_secid);
@@ -2347,10 +2359,26 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
optval, optlen, len);
}
-int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
+int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
+ u32 *secid)
{
- return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
- skb, secid);
+ struct security_hook_list *hp;
+ int rc = -ENOPROTOOPT;
+
+ /*
+ * Only one security module should provide a real hook for
+ * this. A stub or bypass like is used in BPF should either
+ * (somehow) leave rc unaltered or return -ENOPROTOOPT.
+ */
+ hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
+ list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.socket_getpeersec_dgram(sock, skb, secid);
+ if (rc != -ENOPROTOOPT)
+ break;
+ }
+ return rc;
}
EXPORT_SYMBOL(security_socket_getpeersec_dgram);
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 08/25] LSM: Use lsmblob in security_secid_to_secctx
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
2021-07-22 0:47 ` [PATCH v28 07/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 10/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
` (5 subsequent siblings)
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, netdev, netfilter-devel
Change security_secid_to_secctx() to take a lsmblob as input
instead of a u32 secid. It will then call the LSM hooks
using the lsmblob element allocated for that module. The
callers have been updated as well. This allows for the
possibility that more than one module may be called upon
to translate a secid to a string, as can occur in the
audit code.
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netfilter-devel@vger.kernel.org
To: Pablo Neira Ayuso <pablo@netfilter.org>
---
drivers/android/binder.c | 12 +++++++++-
include/linux/security.h | 5 +++--
include/net/scm.h | 7 +++++-
kernel/audit.c | 20 +++++++++++++++--
kernel/auditsc.c | 27 ++++++++++++++++++----
net/ipv4/ip_sockglue.c | 4 +++-
net/netfilter/nf_conntrack_netlink.c | 14 ++++++++++--
net/netfilter/nf_conntrack_standalone.c | 4 +++-
net/netfilter/nfnetlink_queue.c | 11 +++++++--
net/netlabel/netlabel_unlabeled.c | 30 +++++++++++++++++++++----
net/netlabel/netlabel_user.c | 6 ++---
security/security.c | 11 +++++----
12 files changed, 122 insertions(+), 29 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index bcec598b89f2..3e97a6de5e80 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2711,6 +2711,7 @@ static void binder_transaction(struct binder_proc *proc,
if (target_node && target_node->txn_security_ctx) {
u32 secid;
+ struct lsmblob blob;
size_t added_size;
/*
@@ -2723,7 +2724,16 @@ static void binder_transaction(struct binder_proc *proc,
* case well anyway.
*/
security_task_getsecid_obj(proc->tsk, &secid);
- ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
+ /*
+ * Later in this patch set security_task_getsecid() will
+ * provide a lsmblob instead of a secid. lsmblob_init
+ * is used to ensure that all the secids in the lsmblob
+ * get the value returned from security_task_getsecid(),
+ * which means that the one expected by
+ * security_secid_to_secctx() will be set.
+ */
+ lsmblob_init(&blob, secid);
+ ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
if (ret) {
return_error = BR_FAILED_REPLY;
return_error_param = ret;
diff --git a/include/linux/security.h b/include/linux/security.h
index 986a8f4bcd54..ef33be59998e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -547,7 +547,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
void security_release_secctx(char *secdata, u32 seclen);
@@ -1397,7 +1397,8 @@ static inline int security_ismaclabel(const char *name)
return 0;
}
-static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+static inline int security_secid_to_secctx(struct lsmblob *blob,
+ char **secdata, u32 *seclen)
{
return -EOPNOTSUPP;
}
diff --git a/include/net/scm.h b/include/net/scm.h
index 1ce365f4c256..23a35ff1b3f2 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -92,12 +92,17 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
#ifdef CONFIG_SECURITY_NETWORK
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
{
+ struct lsmblob lb;
char *secdata;
u32 seclen;
int err;
if (test_bit(SOCK_PASSSEC, &sock->flags)) {
- err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
+ /* There can only be one security module using the secid,
+ * and the infrastructure will know which it is.
+ */
+ lsmblob_init(&lb, scm->secid);
+ err = security_secid_to_secctx(&lb, &secdata, &seclen);
if (!err) {
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/kernel/audit.c b/kernel/audit.c
index 121d37e700a6..22286163e93e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1442,7 +1442,16 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_SIGNAL_INFO:
len = 0;
if (audit_sig_sid) {
- err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+ struct lsmblob blob;
+
+ /*
+ * lsmblob_init sets all values in the lsmblob
+ * to audit_sig_sid. This is temporary until
+ * audit_sig_sid is converted to a lsmblob, which
+ * happens later in this patch set.
+ */
+ lsmblob_init(&blob, audit_sig_sid);
+ err = security_secid_to_secctx(&blob, &ctx, &len);
if (err)
return err;
}
@@ -2131,12 +2140,19 @@ int audit_log_task_context(struct audit_buffer *ab)
unsigned len;
int error;
u32 sid;
+ struct lsmblob blob;
security_task_getsecid_subj(current, &sid);
if (!sid)
return 0;
- error = security_secid_to_secctx(sid, &ctx, &len);
+ /*
+ * lsmblob_init sets all values in the lsmblob to sid.
+ * This is temporary until security_task_getsecid is converted
+ * to use a lsmblob, which happens later in this patch set.
+ */
+ lsmblob_init(&blob, sid);
+ error = security_secid_to_secctx(&blob, &ctx, &len);
if (error) {
if (error != -EINVAL)
goto error_path;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 447614b7a50b..df8a57c5355d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -677,6 +677,13 @@ static int audit_filter_rules(struct task_struct *tsk,
security_task_getsecid_subj(tsk, &sid);
need_sid = 0;
}
+ /*
+ * lsmblob_init sets all values in the lsmblob
+ * to sid. This is temporary until
+ * security_task_getsecid() is converted to
+ * provide a lsmblob, which happens later in
+ * this patch set.
+ */
lsmblob_init(&blob, sid);
result = security_audit_rule_match(&blob,
f->type, f->op,
@@ -693,6 +700,13 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_isset) {
/* Find files that match */
if (name) {
+ /*
+ * lsmblob_init sets all values in the
+ * lsmblob to sid. This is temporary
+ * until name->osid is converted to a
+ * lsmblob, which happens later in
+ * this patch set.
+ */
lsmblob_init(&blob, name->osid);
result = security_audit_rule_match(
&blob,
@@ -999,6 +1013,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
char *ctx = NULL;
u32 len;
int rc = 0;
+ struct lsmblob blob;
ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
if (!ab)
@@ -1008,7 +1023,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (sid) {
- if (security_secid_to_secctx(sid, &ctx, &len)) {
+ lsmblob_init(&blob, sid);
+ if (security_secid_to_secctx(&blob, &ctx, &len)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
@@ -1252,8 +1268,10 @@ static void show_special(struct audit_context *context, int *call_panic)
if (osid) {
char *ctx = NULL;
u32 len;
+ struct lsmblob blob;
- if (security_secid_to_secctx(osid, &ctx, &len)) {
+ lsmblob_init(&blob, osid);
+ if (security_secid_to_secctx(&blob, &ctx, &len)) {
audit_log_format(ab, " osid=%u", osid);
*call_panic = 1;
} else {
@@ -1408,9 +1426,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
if (n->osid != 0) {
char *ctx = NULL;
u32 len;
+ struct lsmblob blob;
- if (security_secid_to_secctx(
- n->osid, &ctx, &len)) {
+ lsmblob_init(&blob, n->osid);
+ if (security_secid_to_secctx(&blob, &ctx, &len)) {
audit_log_format(ab, " osid=%u", n->osid);
if (call_panic)
*call_panic = 2;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ec6036713e2c..2f089733ada7 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
{
+ struct lsmblob lb;
char *secdata;
u32 seclen, secid;
int err;
@@ -138,7 +139,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
if (err)
return;
- err = security_secid_to_secctx(secid, &secdata, &seclen);
+ lsmblob_init(&lb, secid);
+ err = security_secid_to_secctx(&lb, &secdata, &seclen);
if (err)
return;
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index e81af33b233b..9bf1f5460681 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -341,8 +341,13 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
struct nlattr *nest_secctx;
int len, ret;
char *secctx;
+ struct lsmblob blob;
- ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+ /* lsmblob_init() puts ct->secmark into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, ct->secmark);
+ ret = security_secid_to_secctx(&blob, &secctx, &len);
if (ret)
return 0;
@@ -650,8 +655,13 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
{
#ifdef CONFIG_NF_CONNTRACK_SECMARK
int len, ret;
+ struct lsmblob blob;
- ret = security_secid_to_secctx(ct->secmark, NULL, &len);
+ /* lsmblob_init() puts ct->secmark into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, ct->secmark);
+ ret = security_secid_to_secctx(&blob, NULL, &len);
if (ret)
return 0;
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 214d9f9e499b..89b6f5ebcfc4 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
int ret;
u32 len;
char *secctx;
+ struct lsmblob blob;
- ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+ lsmblob_init(&blob, ct->secmark);
+ ret = security_secid_to_secctx(&blob, &secctx, &len);
if (ret)
return;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index f774de0fc24f..a781e757d593 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -305,13 +305,20 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
{
u32 seclen = 0;
#if IS_ENABLED(CONFIG_NETWORK_SECMARK)
+ struct lsmblob blob;
+
if (!skb || !sk_fullsock(skb->sk))
return 0;
read_lock_bh(&skb->sk->sk_callback_lock);
- if (skb->secmark)
- security_secid_to_secctx(skb->secmark, secdata, &seclen);
+ if (skb->secmark) {
+ /* lsmblob_init() puts ct->secmark into all of the secids in
+ * blob. security_secid_to_secctx() will know which security
+ * module to use to create the secctx. */
+ lsmblob_init(&blob, skb->secmark);
+ security_secid_to_secctx(&blob, secdata, &seclen);
+ }
read_unlock_bh(&skb->sk->sk_callback_lock);
#endif
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index c29a8d7a7070..5cbbc469ac7c 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -376,6 +376,7 @@ int netlbl_unlhsh_add(struct net *net,
struct audit_buffer *audit_buf = NULL;
char *secctx = NULL;
u32 secctx_len;
+ struct lsmblob blob;
if (addr_len != sizeof(struct in_addr) &&
addr_len != sizeof(struct in6_addr))
@@ -438,7 +439,11 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- if (security_secid_to_secctx(secid,
+ /* lsmblob_init() puts secid into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, secid);
+ if (security_secid_to_secctx(&blob,
&secctx,
&secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
@@ -475,6 +480,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct net_device *dev;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -494,8 +500,13 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
addr->s_addr, mask->s_addr);
if (dev != NULL)
dev_put(dev);
+ /* lsmblob_init() puts entry->secid into all of the secids
+ * in blob. security_secid_to_secctx() will know which
+ * security module to use to create the secctx. */
+ if (entry != NULL)
+ lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(entry->secid,
+ security_secid_to_secctx(&blob,
&secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
security_release_secctx(secctx, secctx_len);
@@ -537,6 +548,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct net_device *dev;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -555,8 +567,13 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
addr, mask);
if (dev != NULL)
dev_put(dev);
+ /* lsmblob_init() puts entry->secid into all of the secids
+ * in blob. security_secid_to_secctx() will know which
+ * security module to use to create the secctx. */
+ if (entry != NULL)
+ lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(entry->secid,
+ security_secid_to_secctx(&blob,
&secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
security_release_secctx(secctx, secctx_len);
@@ -1082,6 +1099,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
u32 secid;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;
data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1136,7 +1154,11 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
secid = addr6->secid;
}
- ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
+ /* lsmblob_init() secid into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, secid);
+ ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 3ed4fea2a2de..893301ae0131 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -86,6 +86,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
struct audit_buffer *audit_buf;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;
if (audit_enabled == AUDIT_OFF)
return NULL;
@@ -98,10 +99,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
from_kuid(&init_user_ns, audit_info->loginuid),
audit_info->sessionid);
+ lsmblob_init(&blob, audit_info->secid);
if (audit_info->secid != 0 &&
- security_secid_to_secctx(audit_info->secid,
- &secctx,
- &secctx_len) == 0) {
+ security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " subj=%s", secctx);
security_release_secctx(secctx, secctx_len);
}
diff --git a/security/security.c b/security/security.c
index 1621a28bf9c4..607e54a0e85f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2174,17 +2174,16 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
{
struct security_hook_list *hp;
int rc;
- /*
- * Currently, only one LSM can implement secid_to_secctx (i.e this
- * LSM hook is not "stackable").
- */
hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
- rc = hp->hook.secid_to_secctx(secid, secdata, seclen);
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
+ secdata, seclen);
if (rc != LSM_RET_DEFAULT(secid_to_secctx))
return rc;
}
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 10/25] LSM: Use lsmblob in security_task_getsecid
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
2021-07-22 0:47 ` [PATCH v28 07/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 08/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 15/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
` (4 subsequent siblings)
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, linux-integrity, netdev
Change the security_task_getsecid_subj() and
security_task_getsecid_obj() interfaces to fill in
a lsmblob structure instead of a u32 secid in support of
LSM stacking. Audit interfaces will need to collect all
possible secids for possible reporting.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netdev@vger.kernel.org
---
drivers/android/binder.c | 12 +-----
include/linux/security.h | 14 ++++---
kernel/audit.c | 16 +++-----
kernel/auditfilter.c | 4 +-
kernel/auditsc.c | 25 ++++++------
net/netlabel/netlabel_unlabeled.c | 5 ++-
net/netlabel/netlabel_user.h | 6 ++-
security/integrity/ima/ima_appraise.c | 10 +++--
security/integrity/ima/ima_main.c | 56 +++++++++++++++------------
security/security.c | 25 +++++++++---
10 files changed, 94 insertions(+), 79 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 3e97a6de5e80..96dd728809ef 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2710,7 +2710,6 @@ static void binder_transaction(struct binder_proc *proc,
t->priority = task_nice(current);
if (target_node && target_node->txn_security_ctx) {
- u32 secid;
struct lsmblob blob;
size_t added_size;
@@ -2723,16 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
* here; however, it isn't clear that binder would handle that
* case well anyway.
*/
- security_task_getsecid_obj(proc->tsk, &secid);
- /*
- * Later in this patch set security_task_getsecid() will
- * provide a lsmblob instead of a secid. lsmblob_init
- * is used to ensure that all the secids in the lsmblob
- * get the value returned from security_task_getsecid(),
- * which means that the one expected by
- * security_secid_to_secctx() will be set.
- */
- lsmblob_init(&blob, secid);
+ security_task_getsecid_obj(proc->tsk, &blob);
ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
if (ret) {
return_error = BR_FAILED_REPLY;
diff --git a/include/linux/security.h b/include/linux/security.h
index 886128899d5f..4070cef152f7 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -500,8 +500,8 @@ int security_task_fix_setgid(struct cred *new, const struct cred *old,
int security_task_setpgid(struct task_struct *p, pid_t pgid);
int security_task_getpgid(struct task_struct *p);
int security_task_getsid(struct task_struct *p);
-void security_task_getsecid_subj(struct task_struct *p, u32 *secid);
-void security_task_getsecid_obj(struct task_struct *p, u32 *secid);
+void security_task_getsecid_subj(struct task_struct *p, struct lsmblob *blob);
+void security_task_getsecid_obj(struct task_struct *p, struct lsmblob *blob);
int security_task_setnice(struct task_struct *p, int nice);
int security_task_setioprio(struct task_struct *p, int ioprio);
int security_task_getioprio(struct task_struct *p);
@@ -1197,14 +1197,16 @@ static inline int security_task_getsid(struct task_struct *p)
return 0;
}
-static inline void security_task_getsecid_subj(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid_subj(struct task_struct *p,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob, 0);
}
-static inline void security_task_getsecid_obj(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid_obj(struct task_struct *p,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob, 0);
}
static inline int security_task_setnice(struct task_struct *p, int nice)
diff --git a/kernel/audit.c b/kernel/audit.c
index 22286163e93e..d92c7b894183 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2139,19 +2139,12 @@ int audit_log_task_context(struct audit_buffer *ab)
char *ctx = NULL;
unsigned len;
int error;
- u32 sid;
struct lsmblob blob;
- security_task_getsecid_subj(current, &sid);
- if (!sid)
+ security_task_getsecid_subj(current, &blob);
+ if (!lsmblob_is_set(&blob))
return 0;
- /*
- * lsmblob_init sets all values in the lsmblob to sid.
- * This is temporary until security_task_getsecid is converted
- * to use a lsmblob, which happens later in this patch set.
- */
- lsmblob_init(&blob, sid);
error = security_secid_to_secctx(&blob, &ctx, &len);
if (error) {
if (error != -EINVAL)
@@ -2359,6 +2352,7 @@ int audit_set_loginuid(kuid_t loginuid)
int audit_signal_info(int sig, struct task_struct *t)
{
kuid_t uid = current_uid(), auid;
+ struct lsmblob blob;
if (auditd_test_task(t) &&
(sig == SIGTERM || sig == SIGHUP ||
@@ -2369,7 +2363,9 @@ int audit_signal_info(int sig, struct task_struct *t)
audit_sig_uid = auid;
else
audit_sig_uid = uid;
- security_task_getsecid_subj(current, &audit_sig_sid);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until audit_sig_sid is converted */
+ audit_sig_sid = blob.secid[0];
}
return audit_signal_info_syscall(t);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 6a04d762d272..1ba14a7a38f7 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1330,7 +1330,6 @@ int audit_filter(int msgtype, unsigned int listtype)
for (i = 0; i < e->rule.field_count; i++) {
struct audit_field *f = &e->rule.fields[i];
pid_t pid;
- u32 sid;
struct lsmblob blob;
switch (f->type) {
@@ -1362,8 +1361,7 @@ int audit_filter(int msgtype, unsigned int listtype)
case AUDIT_SUBJ_CLR:
if (f->lsm_isset) {
security_task_getsecid_subj(current,
- &sid);
- lsmblob_init(&blob, sid);
+ &blob);
result = security_audit_rule_match(
&blob, f->type, f->op,
f->lsm_rules);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b4d214b21b97..50e3f2f4cb49 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -477,7 +477,6 @@ static int audit_filter_rules(struct task_struct *tsk,
{
const struct cred *cred;
int i, need_sid = 1;
- u32 sid;
struct lsmblob blob;
unsigned int sessionid;
@@ -674,17 +673,9 @@ static int audit_filter_rules(struct task_struct *tsk,
logged upon error */
if (f->lsm_isset) {
if (need_sid) {
- security_task_getsecid_subj(tsk, &sid);
+ security_task_getsecid_subj(tsk, &blob);
need_sid = 0;
}
- /*
- * lsmblob_init sets all values in the lsmblob
- * to sid. This is temporary until
- * security_task_getsecid() is converted to
- * provide a lsmblob, which happens later in
- * this patch set.
- */
- lsmblob_init(&blob, sid);
result = security_audit_rule_match(&blob,
f->type, f->op,
f->lsm_rules);
@@ -2439,12 +2430,15 @@ int __audit_sockaddr(int len, void *a)
void __audit_ptrace(struct task_struct *t)
{
struct audit_context *context = audit_context();
+ struct lsmblob blob;
context->target_pid = task_tgid_nr(t);
context->target_auid = audit_get_loginuid(t);
context->target_uid = task_uid(t);
context->target_sessionid = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &context->target_sid);
+ security_task_getsecid_obj(t, &blob);
+ /* scaffolding - until target_sid is converted */
+ context->target_sid = blob.secid[0];
memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
}
@@ -2460,6 +2454,7 @@ int audit_signal_info_syscall(struct task_struct *t)
struct audit_aux_data_pids *axp;
struct audit_context *ctx = audit_context();
kuid_t t_uid = task_uid(t);
+ struct lsmblob blob;
if (!audit_signals || audit_dummy_context())
return 0;
@@ -2471,7 +2466,9 @@ int audit_signal_info_syscall(struct task_struct *t)
ctx->target_auid = audit_get_loginuid(t);
ctx->target_uid = t_uid;
ctx->target_sessionid = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &ctx->target_sid);
+ security_task_getsecid_obj(t, &blob);
+ /* scaffolding until target_sid is converted */
+ ctx->target_sid = blob.secid[0];
memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
return 0;
}
@@ -2492,7 +2489,9 @@ int audit_signal_info_syscall(struct task_struct *t)
axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
axp->target_uid[axp->pid_count] = t_uid;
axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &axp->target_sid[axp->pid_count]);
+ security_task_getsecid_obj(t, &blob);
+ /* scaffolding until target_sid is converted */
+ axp->target_sid[axp->pid_count] = blob.secid[0];
memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
axp->pid_count++;
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 5cbbc469ac7c..098d0a1a3330 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1564,11 +1564,14 @@ int __init netlbl_unlabel_defconf(void)
int ret_val;
struct netlbl_dom_map *entry;
struct netlbl_audit audit_info;
+ struct lsmblob blob;
/* Only the kernel is allowed to call this function and the only time
* it is called is at bootup before the audit subsystem is reporting
* messages so don't worry to much about these values. */
- security_task_getsecid_subj(current, &audit_info.secid);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until audit_info.secid is converted */
+ audit_info.secid = blob.secid[0];
audit_info.loginuid = GLOBAL_ROOT_UID;
audit_info.sessionid = 0;
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index 6190cbf94bf0..aa31f7bf79ee 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -32,7 +32,11 @@
*/
static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info)
{
- security_task_getsecid_subj(current, &audit_info->secid);
+ struct lsmblob blob;
+
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until secid is converted */
+ audit_info->secid = blob.secid[0];
audit_info->loginuid = audit_get_loginuid(current);
audit_info->sessionid = audit_get_sessionid(current);
}
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index ef9dcfce45d4..e3d903d6e5e7 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -71,14 +71,16 @@ bool is_ima_appraise_enabled(void)
int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
int mask, enum ima_hooks func)
{
- u32 secid;
+ struct lsmblob blob;
if (!ima_appraise)
return 0;
- security_task_getsecid_subj(current, &secid);
- return ima_match_policy(mnt_userns, inode, current_cred(), secid, func,
- mask, IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding the .secid[0] */
+ return ima_match_policy(mnt_userns, inode, current_cred(),
+ blob.secid[0], func, mask,
+ IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
}
static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 287b90509006..29befd24b945 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -388,12 +388,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
*/
int ima_file_mmap(struct file *file, unsigned long prot)
{
- u32 secid;
+ struct lsmblob blob;
if (file && (prot & PROT_EXEC)) {
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, NULL,
- 0, MAY_EXEC, MMAP_CHECK);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding - until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0],
+ NULL, 0, MAY_EXEC, MMAP_CHECK);
}
return 0;
@@ -419,9 +420,9 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
char *pathbuf = NULL;
const char *pathname = NULL;
struct inode *inode;
+ struct lsmblob blob;
int result = 0;
int action;
- u32 secid;
int pcr;
/* Is mprotect making an mmap'ed file executable? */
@@ -429,11 +430,12 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
!(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
return 0;
- security_task_getsecid_subj(current, &secid);
+ security_task_getsecid_subj(current, &blob);
inode = file_inode(vma->vm_file);
+ /* scaffolding */
action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
- current_cred(), secid, MAY_EXEC, MMAP_CHECK,
- &pcr, &template, NULL);
+ current_cred(), blob.secid[0], MAY_EXEC,
+ MMAP_CHECK, &pcr, &template, NULL);
/* Is the mmap'ed file in policy? */
if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
@@ -469,10 +471,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
{
int ret;
u32 secid;
+ struct lsmblob blob;
- security_task_getsecid_subj(current, &secid);
- ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
- MAY_EXEC, BPRM_CHECK);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until process_measurement changes */
+ ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
+ NULL, 0, MAY_EXEC, BPRM_CHECK);
if (ret)
return ret;
@@ -493,10 +497,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
*/
int ima_file_check(struct file *file, int mask)
{
- u32 secid;
+ struct lsmblob blob;
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, NULL, 0,
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
MAY_APPEND), FILE_CHECK);
}
@@ -672,7 +677,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
bool contents)
{
enum ima_hooks func;
- u32 secid;
+ struct lsmblob blob;
/*
* Do devices using pre-allocated memory run the risk of the
@@ -692,8 +697,9 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
/* Read entire file for all partial reads. */
func = read_idmap[read_id] ?: FILE_CHECK;
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, NULL,
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding - until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0], NULL,
0, MAY_READ, func);
}
@@ -722,7 +728,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id read_id)
{
enum ima_hooks func;
- u32 secid;
+ struct lsmblob blob;
/* permit signed certs */
if (!file && read_id == READING_X509_CERTIFICATE)
@@ -735,9 +741,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
}
func = read_idmap[read_id] ?: FILE_CHECK;
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, buf, size,
- MAY_READ, func);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0], buf,
+ size, MAY_READ, func);
}
/**
@@ -859,7 +866,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
int digest_hash_len = hash_digest_size[ima_hash_algo];
int violation = 0;
int action = 0;
- u32 secid;
+ struct lsmblob blob;
if (!ima_policy_flag)
return;
@@ -879,9 +886,10 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
* buffer measurements.
*/
if (func) {
- security_task_getsecid_subj(current, &secid);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding */
action = ima_get_action(mnt_userns, inode, current_cred(),
- secid, 0, func, &pcr, &template,
+ blob.secid[0], 0, func, &pcr, &template,
func_data);
if (!(action & IMA_MEASURE))
return;
diff --git a/security/security.c b/security/security.c
index c38816ef9778..458fded340ab 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1904,17 +1904,30 @@ int security_task_getsid(struct task_struct *p)
return call_int_hook(task_getsid, 0, p);
}
-void security_task_getsecid_subj(struct task_struct *p, u32 *secid)
+void security_task_getsecid_subj(struct task_struct *p, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(task_getsecid_subj, p, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.task_getsecid_subj,
+ list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.task_getsecid_subj(p, &blob->secid[hp->lsmid->slot]);
+ }
}
EXPORT_SYMBOL(security_task_getsecid_subj);
-void security_task_getsecid_obj(struct task_struct *p, u32 *secid)
+void security_task_getsecid_obj(struct task_struct *p, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(task_getsecid_obj, p, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.task_getsecid_obj, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.task_getsecid_obj(p, &blob->secid[hp->lsmid->slot]);
+ }
}
EXPORT_SYMBOL(security_task_getsecid_obj);
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 15/25] LSM: Ensure the correct LSM context releaser
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
` (2 preceding siblings ...)
2021-07-22 0:47 ` [PATCH v28 10/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 16/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
` (3 subsequent siblings)
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, Chuck Lever, linux-integrity, netdev,
netfilter-devel, linux-nfs
Add a new lsmcontext data structure to hold all the information
about a "security context", including the string, its size and
which LSM allocated the string. The allocation information is
necessary because LSMs have different policies regarding the
lifecycle of these strings. SELinux allocates and destroys
them on each use, whereas Smack provides a pointer to an entry
in a list that never goes away.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netfilter-devel@vger.kernel.org
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: linux-nfs@vger.kernel.org
---
drivers/android/binder.c | 10 ++++---
fs/ceph/xattr.c | 6 ++++-
fs/nfs/nfs4proc.c | 8 ++++--
fs/nfsd/nfs4xdr.c | 7 +++--
include/linux/security.h | 35 +++++++++++++++++++++++--
include/net/scm.h | 5 +++-
kernel/audit.c | 14 +++++++---
kernel/auditsc.c | 12 ++++++---
net/ipv4/ip_sockglue.c | 4 ++-
net/netfilter/nf_conntrack_netlink.c | 4 ++-
net/netfilter/nf_conntrack_standalone.c | 4 ++-
net/netfilter/nfnetlink_queue.c | 13 ++++++---
net/netlabel/netlabel_unlabeled.c | 19 +++++++++++---
net/netlabel/netlabel_user.c | 4 ++-
security/security.c | 11 ++++----
15 files changed, 121 insertions(+), 35 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 96dd728809ef..8976ac6a5adb 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2461,6 +2461,7 @@ static void binder_transaction(struct binder_proc *proc,
int t_debug_id = atomic_inc_return(&binder_last_id);
char *secctx = NULL;
u32 secctx_sz = 0;
+ struct lsmcontext scaff; /* scaffolding */
e = binder_transaction_log_add(&binder_transaction_log);
e->debug_id = t_debug_id;
@@ -2772,7 +2773,8 @@ static void binder_transaction(struct binder_proc *proc,
t->security_ctx = 0;
WARN_ON(1);
}
- security_release_secctx(secctx, secctx_sz);
+ lsmcontext_init(&scaff, secctx, secctx_sz, 0);
+ security_release_secctx(&scaff);
secctx = NULL;
}
t->buffer->debug_id = t->debug_id;
@@ -3114,8 +3116,10 @@ static void binder_transaction(struct binder_proc *proc,
binder_alloc_free_buf(&target_proc->alloc, t->buffer);
err_binder_alloc_buf_failed:
err_bad_extra_size:
- if (secctx)
- security_release_secctx(secctx, secctx_sz);
+ if (secctx) {
+ lsmcontext_init(&scaff, secctx, secctx_sz, 0);
+ security_release_secctx(&scaff);
+ }
err_get_secctx_failed:
kfree(tcomplete);
binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 1242db8d3444..b867089e1aa4 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1356,12 +1356,16 @@ int ceph_security_init_secctx(struct dentry *dentry, umode_t mode,
void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
{
+#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
+ struct lsmcontext scaff; /* scaffolding */
+#endif
#ifdef CONFIG_CEPH_FS_POSIX_ACL
posix_acl_release(as_ctx->acl);
posix_acl_release(as_ctx->default_acl);
#endif
#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
- security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen);
+ lsmcontext_init(&scaff, as_ctx->sec_ctx, as_ctx->sec_ctxlen, 0);
+ security_release_secctx(&scaff);
#endif
if (as_ctx->pagelist)
ceph_pagelist_release(as_ctx->pagelist);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e1214bb6b7ee..71004670455b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -136,8 +136,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
static inline void
nfs4_label_release_security(struct nfs4_label *label)
{
- if (label)
- security_release_secctx(label->label, label->len);
+ struct lsmcontext scaff; /* scaffolding */
+
+ if (label) {
+ lsmcontext_init(&scaff, label->label, label->len, 0);
+ security_release_secctx(&scaff);
+ }
}
static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
{
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 7abeccb975b2..089ec4b61ef1 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2844,6 +2844,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
int err;
struct nfs4_acl *acl = NULL;
#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+ struct lsmcontext scaff; /* scaffolding */
void *context = NULL;
int contextlen;
#endif
@@ -3345,8 +3346,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
out:
#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
- if (context)
- security_release_secctx(context, contextlen);
+ if (context) {
+ lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
+ security_release_secctx(&scaff);
+ }
#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
kfree(acl);
if (tempfh) {
diff --git a/include/linux/security.h b/include/linux/security.h
index cdd8d9122795..041e87f3fe4e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -133,6 +133,37 @@ enum lockdown_reason {
extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
+/*
+ * A "security context" is the text representation of
+ * the information used by LSMs.
+ * This structure contains the string, its length, and which LSM
+ * it is useful for.
+ */
+struct lsmcontext {
+ char *context; /* Provided by the module */
+ u32 len;
+ int slot; /* Identifies the module */
+};
+
+/**
+ * lsmcontext_init - initialize an lsmcontext structure.
+ * @cp: Pointer to the context to initialize
+ * @context: Initial context, or NULL
+ * @size: Size of context, or 0
+ * @slot: Which LSM provided the context
+ *
+ * Fill in the lsmcontext from the provided information.
+ * This is a scaffolding function that will be removed when
+ * lsmcontext integration is complete.
+ */
+static inline void lsmcontext_init(struct lsmcontext *cp, char *context,
+ u32 size, int slot)
+{
+ cp->slot = slot;
+ cp->context = context;
+ cp->len = size;
+}
+
/*
* Data exported by the security modules
*
@@ -550,7 +581,7 @@ int security_ismaclabel(const char *name);
int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
-void security_release_secctx(char *secdata, u32 seclen);
+void security_release_secctx(struct lsmcontext *cp);
void security_inode_invalidate_secctx(struct inode *inode);
int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
@@ -1414,7 +1445,7 @@ static inline int security_secctx_to_secid(const char *secdata,
return -EOPNOTSUPP;
}
-static inline void security_release_secctx(char *secdata, u32 seclen)
+static inline void security_release_secctx(struct lsmcontext *cp)
{
}
diff --git a/include/net/scm.h b/include/net/scm.h
index 23a35ff1b3f2..f273c4d777ec 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
#ifdef CONFIG_SECURITY_NETWORK
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
{
+ struct lsmcontext context;
struct lsmblob lb;
char *secdata;
u32 seclen;
@@ -106,7 +107,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
if (!err) {
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
- security_release_secctx(secdata, seclen);
+ /*scaffolding*/
+ lsmcontext_init(&context, secdata, seclen, 0);
+ security_release_secctx(&context);
}
}
}
diff --git a/kernel/audit.c b/kernel/audit.c
index 8ec64e6e8bc0..c17ec23158c4 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1192,6 +1192,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct audit_sig_info *sig_data;
char *ctx = NULL;
u32 len;
+ struct lsmcontext scaff; /* scaffolding */
err = audit_netlink_ok(skb, msg_type);
if (err)
@@ -1449,15 +1450,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
}
sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
if (!sig_data) {
- if (lsmblob_is_set(&audit_sig_lsm))
- security_release_secctx(ctx, len);
+ if (lsmblob_is_set(&audit_sig_lsm)) {
+ lsmcontext_init(&scaff, ctx, len, 0);
+ security_release_secctx(&scaff);
+ }
return -ENOMEM;
}
sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
sig_data->pid = audit_sig_pid;
if (lsmblob_is_set(&audit_sig_lsm)) {
memcpy(sig_data->ctx, ctx, len);
- security_release_secctx(ctx, len);
+ lsmcontext_init(&scaff, ctx, len, 0);
+ security_release_secctx(&scaff);
}
audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
sig_data, sizeof(*sig_data) + len);
@@ -2132,6 +2136,7 @@ int audit_log_task_context(struct audit_buffer *ab)
unsigned len;
int error;
struct lsmblob blob;
+ struct lsmcontext scaff; /* scaffolding */
security_task_getsecid_subj(current, &blob);
if (!lsmblob_is_set(&blob))
@@ -2145,7 +2150,8 @@ int audit_log_task_context(struct audit_buffer *ab)
}
audit_log_format(ab, " subj=%s", ctx);
- security_release_secctx(ctx, len);
+ lsmcontext_init(&scaff, ctx, len, 0);
+ security_release_secctx(&scaff);
return 0;
error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b5807b9b8a4d..1b1ddd62de6c 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1002,6 +1002,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
struct lsmblob *blob, char *comm)
{
struct audit_buffer *ab;
+ struct lsmcontext lsmcxt;
char *ctx = NULL;
u32 len;
int rc = 0;
@@ -1019,7 +1020,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
rc = 1;
} else {
audit_log_format(ab, " obj=%s", ctx);
- security_release_secctx(ctx, len);
+ lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
+ security_release_secctx(&lsmcxt);
}
}
audit_log_format(ab, " ocomm=");
@@ -1232,6 +1234,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
static void show_special(struct audit_context *context, int *call_panic)
{
+ struct lsmcontext lsmcxt;
struct audit_buffer *ab;
int i;
@@ -1266,7 +1269,8 @@ static void show_special(struct audit_context *context, int *call_panic)
*call_panic = 1;
} else {
audit_log_format(ab, " obj=%s", ctx);
- security_release_secctx(ctx, len);
+ lsmcontext_init(&lsmcxt, ctx, len, 0);
+ security_release_secctx(&lsmcxt);
}
}
if (context->ipc.has_perm) {
@@ -1417,6 +1421,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
char *ctx = NULL;
u32 len;
struct lsmblob blob;
+ struct lsmcontext lsmcxt;
lsmblob_init(&blob, n->osid);
if (security_secid_to_secctx(&blob, &ctx, &len)) {
@@ -1425,7 +1430,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
*call_panic = 2;
} else {
audit_log_format(ab, " obj=%s", ctx);
- security_release_secctx(ctx, len);
+ lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
+ security_release_secctx(&lsmcxt);
}
}
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 2f089733ada7..a7e4c1b34b6c 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
{
+ struct lsmcontext context;
struct lsmblob lb;
char *secdata;
u32 seclen, secid;
@@ -145,7 +146,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
return;
put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
- security_release_secctx(secdata, seclen);
+ lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+ security_release_secctx(&context);
}
static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9bf1f5460681..89be957f26bd 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -342,6 +342,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
int len, ret;
char *secctx;
struct lsmblob blob;
+ struct lsmcontext context;
/* lsmblob_init() puts ct->secmark into all of the secids in blob.
* security_secid_to_secctx() will know which security module
@@ -362,7 +363,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
ret = 0;
nla_put_failure:
- security_release_secctx(secctx, len);
+ lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
+ security_release_secctx(&context);
return ret;
}
#else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 89b6f5ebcfc4..ca2ae290d6ee 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -176,6 +176,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
u32 len;
char *secctx;
struct lsmblob blob;
+ struct lsmcontext context;
lsmblob_init(&blob, ct->secmark);
ret = security_secid_to_secctx(&blob, &secctx, &len);
@@ -184,7 +185,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
seq_printf(s, "secctx=%s ", secctx);
- security_release_secctx(secctx, len);
+ lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
+ security_release_secctx(&context);
}
#else
static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index a781e757d593..005900a0c397 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -397,6 +397,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
enum ip_conntrack_info ctinfo;
struct nfnl_ct_hook *nfnl_ct;
bool csum_verify;
+ struct lsmcontext scaff; /* scaffolding */
char *secdata = NULL;
u32 seclen = 0;
@@ -626,8 +627,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
}
nlh->nlmsg_len = skb->len;
- if (seclen)
- security_release_secctx(secdata, seclen);
+ if (seclen) {
+ lsmcontext_init(&scaff, secdata, seclen, 0);
+ security_release_secctx(&scaff);
+ }
return skb;
nla_put_failure:
@@ -635,8 +638,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
kfree_skb(skb);
net_err_ratelimited("nf_queue: error creating packet message\n");
nlmsg_failure:
- if (seclen)
- security_release_secctx(secdata, seclen);
+ if (seclen) {
+ lsmcontext_init(&scaff, secdata, seclen, 0);
+ security_release_secctx(&scaff);
+ }
return NULL;
}
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 098d0a1a3330..61346aaa2898 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -374,6 +374,7 @@ int netlbl_unlhsh_add(struct net *net,
struct net_device *dev;
struct netlbl_unlhsh_iface *iface;
struct audit_buffer *audit_buf = NULL;
+ struct lsmcontext context;
char *secctx = NULL;
u32 secctx_len;
struct lsmblob blob;
@@ -447,7 +448,9 @@ int netlbl_unlhsh_add(struct net *net,
&secctx,
&secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
- security_release_secctx(secctx, secctx_len);
+ /* scaffolding */
+ lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
audit_log_end(audit_buf);
@@ -478,6 +481,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct netlbl_unlhsh_addr4 *entry;
struct audit_buffer *audit_buf;
struct net_device *dev;
+ struct lsmcontext context;
char *secctx;
u32 secctx_len;
struct lsmblob blob;
@@ -509,7 +513,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
security_secid_to_secctx(&blob,
&secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
- security_release_secctx(secctx, secctx_len);
+ /* scaffolding */
+ lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
audit_log_end(audit_buf);
@@ -546,6 +552,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct netlbl_unlhsh_addr6 *entry;
struct audit_buffer *audit_buf;
struct net_device *dev;
+ struct lsmcontext context;
char *secctx;
u32 secctx_len;
struct lsmblob blob;
@@ -576,7 +583,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
security_secid_to_secctx(&blob,
&secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
- security_release_secctx(secctx, secctx_len);
+ lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
audit_log_end(audit_buf);
@@ -1095,6 +1103,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
int ret_val = -ENOMEM;
struct netlbl_unlhsh_walk_arg *cb_arg = arg;
struct net_device *dev;
+ struct lsmcontext context;
void *data;
u32 secid;
char *secctx;
@@ -1165,7 +1174,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
NLBL_UNLABEL_A_SECCTX,
secctx_len,
secctx);
- security_release_secctx(secctx, secctx_len);
+ /* scaffolding */
+ lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_release_secctx(&context);
if (ret_val != 0)
goto list_cb_failure;
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 893301ae0131..ef139d8ae7cd 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -84,6 +84,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
struct netlbl_audit *audit_info)
{
struct audit_buffer *audit_buf;
+ struct lsmcontext context;
char *secctx;
u32 secctx_len;
struct lsmblob blob;
@@ -103,7 +104,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
if (audit_info->secid != 0 &&
security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " subj=%s", secctx);
- security_release_secctx(secctx, secctx_len);
+ lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+ security_release_secctx(&context);
}
return audit_buf;
diff --git a/security/security.c b/security/security.c
index 7829b8f5d15f..4cb540d93ab8 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2361,16 +2361,17 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
}
EXPORT_SYMBOL(security_secctx_to_secid);
-void security_release_secctx(char *secdata, u32 seclen)
+void security_release_secctx(struct lsmcontext *cp)
{
struct security_hook_list *hp;
- int ilsm = lsm_task_ilsm(current);
hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
- if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
- hp->hook.release_secctx(secdata, seclen);
- return;
+ if (cp->slot == hp->lsmid->slot) {
+ hp->hook.release_secctx(cp->context, cp->len);
+ break;
}
+
+ memset(cp, 0, sizeof(*cp));
}
EXPORT_SYMBOL(security_release_secctx);
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 16/25] LSM: Use lsmcontext in security_secid_to_secctx
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
` (3 preceding siblings ...)
2021-07-22 0:47 ` [PATCH v28 15/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
` (2 subsequent siblings)
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, netdev, netfilter-devel
Replace the (secctx,seclen) pointer pair with a single
lsmcontext pointer to allow return of the LSM identifier
along with the context and context length. This allows
security_release_secctx() to know how to release the
context. Callers have been modified to use or save the
returned data from the new structure.
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netfilter-devel@vger.kernel.org
---
drivers/android/binder.c | 26 +++++++---------
include/linux/security.h | 4 +--
include/net/scm.h | 9 ++----
kernel/audit.c | 39 +++++++++++-------------
kernel/auditsc.c | 31 +++++++------------
net/ipv4/ip_sockglue.c | 8 ++---
net/netfilter/nf_conntrack_netlink.c | 18 +++++------
net/netfilter/nf_conntrack_standalone.c | 7 ++---
net/netfilter/nfnetlink_queue.c | 5 +++-
net/netlabel/netlabel_unlabeled.c | 40 ++++++++-----------------
net/netlabel/netlabel_user.c | 7 ++---
security/security.c | 10 +++++--
12 files changed, 81 insertions(+), 123 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8976ac6a5adb..2c3a2348a144 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2459,9 +2459,7 @@ static void binder_transaction(struct binder_proc *proc,
binder_size_t last_fixup_min_off = 0;
struct binder_context *context = proc->context;
int t_debug_id = atomic_inc_return(&binder_last_id);
- char *secctx = NULL;
- u32 secctx_sz = 0;
- struct lsmcontext scaff; /* scaffolding */
+ struct lsmcontext lsmctx = { };
e = binder_transaction_log_add(&binder_transaction_log);
e->debug_id = t_debug_id;
@@ -2724,14 +2722,14 @@ static void binder_transaction(struct binder_proc *proc,
* case well anyway.
*/
security_task_getsecid_obj(proc->tsk, &blob);
- ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
+ ret = security_secid_to_secctx(&blob, &lsmctx);
if (ret) {
return_error = BR_FAILED_REPLY;
return_error_param = ret;
return_error_line = __LINE__;
goto err_get_secctx_failed;
}
- added_size = ALIGN(secctx_sz, sizeof(u64));
+ added_size = ALIGN(lsmctx.len, sizeof(u64));
extra_buffers_size += added_size;
if (extra_buffers_size < added_size) {
/* integer overflow of extra_buffers_size */
@@ -2758,24 +2756,22 @@ static void binder_transaction(struct binder_proc *proc,
t->buffer = NULL;
goto err_binder_alloc_buf_failed;
}
- if (secctx) {
+ if (lsmctx.context) {
int err;
size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
ALIGN(tr->offsets_size, sizeof(void *)) +
ALIGN(extra_buffers_size, sizeof(void *)) -
- ALIGN(secctx_sz, sizeof(u64));
+ ALIGN(lsmctx.len, sizeof(u64));
t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
err = binder_alloc_copy_to_buffer(&target_proc->alloc,
t->buffer, buf_offset,
- secctx, secctx_sz);
+ lsmctx.context, lsmctx.len);
if (err) {
t->security_ctx = 0;
WARN_ON(1);
}
- lsmcontext_init(&scaff, secctx, secctx_sz, 0);
- security_release_secctx(&scaff);
- secctx = NULL;
+ security_release_secctx(&lsmctx);
}
t->buffer->debug_id = t->debug_id;
t->buffer->transaction = t;
@@ -2832,7 +2828,7 @@ static void binder_transaction(struct binder_proc *proc,
off_end_offset = off_start_offset + tr->offsets_size;
sg_buf_offset = ALIGN(off_end_offset, sizeof(void *));
sg_buf_end_offset = sg_buf_offset + extra_buffers_size -
- ALIGN(secctx_sz, sizeof(u64));
+ ALIGN(lsmctx.len, sizeof(u64));
off_min = 0;
for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
buffer_offset += sizeof(binder_size_t)) {
@@ -3116,10 +3112,8 @@ static void binder_transaction(struct binder_proc *proc,
binder_alloc_free_buf(&target_proc->alloc, t->buffer);
err_binder_alloc_buf_failed:
err_bad_extra_size:
- if (secctx) {
- lsmcontext_init(&scaff, secctx, secctx_sz, 0);
- security_release_secctx(&scaff);
- }
+ if (lsmctx.context)
+ security_release_secctx(&lsmctx);
err_get_secctx_failed:
kfree(tcomplete);
binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/include/linux/security.h b/include/linux/security.h
index 041e87f3fe4e..b19bd9e1d583 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -578,7 +578,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
void security_release_secctx(struct lsmcontext *cp);
@@ -1433,7 +1433,7 @@ static inline int security_ismaclabel(const char *name)
}
static inline int security_secid_to_secctx(struct lsmblob *blob,
- char **secdata, u32 *seclen)
+ struct lsmcontext *cp)
{
return -EOPNOTSUPP;
}
diff --git a/include/net/scm.h b/include/net/scm.h
index f273c4d777ec..b77a52f93389 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -94,8 +94,6 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
{
struct lsmcontext context;
struct lsmblob lb;
- char *secdata;
- u32 seclen;
int err;
if (test_bit(SOCK_PASSSEC, &sock->flags)) {
@@ -103,12 +101,11 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
* and the infrastructure will know which it is.
*/
lsmblob_init(&lb, scm->secid);
- err = security_secid_to_secctx(&lb, &secdata, &seclen);
+ err = security_secid_to_secctx(&lb, &context);
if (!err) {
- put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
- /*scaffolding*/
- lsmcontext_init(&context, secdata, seclen, 0);
+ put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
+ context.context);
security_release_secctx(&context);
}
}
diff --git a/kernel/audit.c b/kernel/audit.c
index c17ec23158c4..841123390d41 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1190,9 +1190,6 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
struct audit_sig_info *sig_data;
- char *ctx = NULL;
- u32 len;
- struct lsmcontext scaff; /* scaffolding */
err = audit_netlink_ok(skb, msg_type);
if (err)
@@ -1440,33 +1437,34 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
kfree(new);
break;
}
- case AUDIT_SIGNAL_INFO:
- len = 0;
+ case AUDIT_SIGNAL_INFO: {
+ struct lsmcontext context = { };
+ int len = 0;
+
if (lsmblob_is_set(&audit_sig_lsm)) {
- err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
- &len);
+ err = security_secid_to_secctx(&audit_sig_lsm,
+ &context);
if (err)
return err;
}
- sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
+ sig_data = kmalloc(sizeof(*sig_data) + context.len, GFP_KERNEL);
if (!sig_data) {
- if (lsmblob_is_set(&audit_sig_lsm)) {
- lsmcontext_init(&scaff, ctx, len, 0);
- security_release_secctx(&scaff);
- }
+ if (lsmblob_is_set(&audit_sig_lsm))
+ security_release_secctx(&context);
return -ENOMEM;
}
sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
sig_data->pid = audit_sig_pid;
if (lsmblob_is_set(&audit_sig_lsm)) {
- memcpy(sig_data->ctx, ctx, len);
- lsmcontext_init(&scaff, ctx, len, 0);
- security_release_secctx(&scaff);
+ len = context.len;
+ memcpy(sig_data->ctx, context.context, len);
+ security_release_secctx(&context);
}
audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
sig_data, sizeof(*sig_data) + len);
kfree(sig_data);
break;
+ }
case AUDIT_TTY_GET: {
struct audit_tty_status s;
unsigned int t;
@@ -2132,26 +2130,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)
int audit_log_task_context(struct audit_buffer *ab)
{
- char *ctx = NULL;
- unsigned len;
int error;
struct lsmblob blob;
- struct lsmcontext scaff; /* scaffolding */
+ struct lsmcontext context;
security_task_getsecid_subj(current, &blob);
if (!lsmblob_is_set(&blob))
return 0;
- error = security_secid_to_secctx(&blob, &ctx, &len);
+ error = security_secid_to_secctx(&blob, &context);
if (error) {
if (error != -EINVAL)
goto error_path;
return 0;
}
- audit_log_format(ab, " subj=%s", ctx);
- lsmcontext_init(&scaff, ctx, len, 0);
- security_release_secctx(&scaff);
+ audit_log_format(ab, " subj=%s", context.context);
+ security_release_secctx(&context);
return 0;
error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 1b1ddd62de6c..d198f307a4d8 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1002,9 +1002,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
struct lsmblob *blob, char *comm)
{
struct audit_buffer *ab;
- struct lsmcontext lsmcxt;
- char *ctx = NULL;
- u32 len;
+ struct lsmcontext lsmctx;
int rc = 0;
ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -1015,13 +1013,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (lsmblob_is_set(blob)) {
- if (security_secid_to_secctx(blob, &ctx, &len)) {
+ if (security_secid_to_secctx(blob, &lsmctx)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
- security_release_secctx(&lsmcxt);
+ audit_log_format(ab, " obj=%s", lsmctx.context);
+ security_release_secctx(&lsmctx);
}
}
audit_log_format(ab, " ocomm=");
@@ -1234,7 +1231,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
static void show_special(struct audit_context *context, int *call_panic)
{
- struct lsmcontext lsmcxt;
struct audit_buffer *ab;
int i;
@@ -1259,17 +1255,15 @@ static void show_special(struct audit_context *context, int *call_panic)
from_kgid(&init_user_ns, context->ipc.gid),
context->ipc.mode);
if (osid) {
- char *ctx = NULL;
- u32 len;
+ struct lsmcontext lsmcxt;
struct lsmblob blob;
lsmblob_init(&blob, osid);
- if (security_secid_to_secctx(&blob, &ctx, &len)) {
+ if (security_secid_to_secctx(&blob, &lsmcxt)) {
audit_log_format(ab, " osid=%u", osid);
*call_panic = 1;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0);
+ audit_log_format(ab, " obj=%s", lsmcxt.context);
security_release_secctx(&lsmcxt);
}
}
@@ -1418,20 +1412,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
MAJOR(n->rdev),
MINOR(n->rdev));
if (n->osid != 0) {
- char *ctx = NULL;
- u32 len;
struct lsmblob blob;
- struct lsmcontext lsmcxt;
+ struct lsmcontext lsmctx;
lsmblob_init(&blob, n->osid);
- if (security_secid_to_secctx(&blob, &ctx, &len)) {
+ if (security_secid_to_secctx(&blob, &lsmctx)) {
audit_log_format(ab, " osid=%u", n->osid);
if (call_panic)
*call_panic = 2;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
- security_release_secctx(&lsmcxt);
+ audit_log_format(ab, " obj=%s", lsmctx.context);
+ security_release_secctx(&lsmctx);
}
}
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index a7e4c1b34b6c..ae073b642fa7 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -132,8 +132,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
{
struct lsmcontext context;
struct lsmblob lb;
- char *secdata;
- u32 seclen, secid;
+ u32 secid;
int err;
err = security_socket_getpeersec_dgram(NULL, skb, &secid);
@@ -141,12 +140,11 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
return;
lsmblob_init(&lb, secid);
- err = security_secid_to_secctx(&lb, &secdata, &seclen);
+ err = security_secid_to_secctx(&lb, &context);
if (err)
return;
- put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
- lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+ put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
security_release_secctx(&context);
}
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 89be957f26bd..668b31ecd638 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -339,8 +339,7 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
{
struct nlattr *nest_secctx;
- int len, ret;
- char *secctx;
+ int ret;
struct lsmblob blob;
struct lsmcontext context;
@@ -348,7 +347,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &secctx, &len);
+ ret = security_secid_to_secctx(&blob, &context);
if (ret)
return 0;
@@ -357,13 +356,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
if (!nest_secctx)
goto nla_put_failure;
- if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
+ if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
goto nla_put_failure;
nla_nest_end(skb, nest_secctx);
ret = 0;
nla_put_failure:
- lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
security_release_secctx(&context);
return ret;
}
@@ -658,15 +656,15 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
#ifdef CONFIG_NF_CONNTRACK_SECMARK
int len, ret;
struct lsmblob blob;
+ struct lsmcontext context;
- /* lsmblob_init() puts ct->secmark into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, NULL, &len);
+ ret = security_secid_to_secctx(&blob, &context);
if (ret)
return 0;
+ len = context.len;
+ security_release_secctx(&context);
+
return nla_total_size(0) /* CTA_SECCTX */
+ nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
#else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index ca2ae290d6ee..b5796a8e5e90 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
{
int ret;
- u32 len;
- char *secctx;
struct lsmblob blob;
struct lsmcontext context;
lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &secctx, &len);
+ ret = security_secid_to_secctx(&blob, &context);
if (ret)
return;
- seq_printf(s, "secctx=%s ", secctx);
+ seq_printf(s, "secctx=%s ", context.context);
- lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
security_release_secctx(&context);
}
#else
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 005900a0c397..d5cff4559237 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -306,6 +306,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
u32 seclen = 0;
#if IS_ENABLED(CONFIG_NETWORK_SECMARK)
struct lsmblob blob;
+ struct lsmcontext context = { };
if (!skb || !sk_fullsock(skb->sk))
return 0;
@@ -317,10 +318,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
* blob. security_secid_to_secctx() will know which security
* module to use to create the secctx. */
lsmblob_init(&blob, skb->secmark);
- security_secid_to_secctx(&blob, secdata, &seclen);
+ security_secid_to_secctx(&blob, &context);
+ *secdata = context.context;
}
read_unlock_bh(&skb->sk->sk_callback_lock);
+ seclen = context.len;
#endif
return seclen;
}
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 61346aaa2898..9910d3e9d287 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -375,8 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
struct netlbl_unlhsh_iface *iface;
struct audit_buffer *audit_buf = NULL;
struct lsmcontext context;
- char *secctx = NULL;
- u32 secctx_len;
struct lsmblob blob;
if (addr_len != sizeof(struct in_addr) &&
@@ -444,12 +442,9 @@ int netlbl_unlhsh_add(struct net *net,
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, secid);
- if (security_secid_to_secctx(&blob,
- &secctx,
- &secctx_len) == 0) {
- audit_log_format(audit_buf, " sec_obj=%s", secctx);
- /* scaffolding */
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ if (security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " sec_obj=%s",
+ context.context);
security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
@@ -482,8 +477,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
@@ -510,11 +503,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
if (entry != NULL)
lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob,
- &secctx, &secctx_len) == 0) {
- audit_log_format(audit_buf, " sec_obj=%s", secctx);
- /* scaffolding */
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " sec_obj=%s",
+ context.context);
security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -553,8 +544,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
@@ -580,10 +569,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
if (entry != NULL)
lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob,
- &secctx, &secctx_len) == 0) {
- audit_log_format(audit_buf, " sec_obj=%s", secctx);
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " sec_obj=%s",
+ context.context);
security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -1106,8 +1094,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
struct lsmcontext context;
void *data;
u32 secid;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;
data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
@@ -1167,15 +1153,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, secid);
- ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
+ ret_val = security_secid_to_secctx(&blob, &context);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
NLBL_UNLABEL_A_SECCTX,
- secctx_len,
- secctx);
- /* scaffolding */
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ context.len,
+ context.context);
security_release_secctx(&context);
if (ret_val != 0)
goto list_cb_failure;
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index ef139d8ae7cd..951ba0639d20 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,8 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
{
struct audit_buffer *audit_buf;
struct lsmcontext context;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;
if (audit_enabled == AUDIT_OFF)
@@ -102,9 +100,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
lsmblob_init(&blob, audit_info->secid);
if (audit_info->secid != 0 &&
- security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
- audit_log_format(audit_buf, " subj=%s", secctx);
- lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+ security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " subj=%s", context.context);
security_release_secctx(&context);
}
diff --git a/security/security.c b/security/security.c
index 4cb540d93ab8..713e0340a0d4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2325,18 +2325,22 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
{
struct security_hook_list *hp;
int ilsm = lsm_task_ilsm(current);
+ memset(cp, 0, sizeof(*cp));
+
hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+ if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
+ cp->slot = hp->lsmid->slot;
return hp->hook.secid_to_secctx(
blob->secid[hp->lsmid->slot],
- secdata, seclen);
+ &cp->context, &cp->len);
+ }
}
return LSM_RET_DEFAULT(secid_to_secctx);
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 18/25] LSM: security_secid_to_secctx in netlink netfilter
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
` (4 preceding siblings ...)
2021-07-22 0:47 ` [PATCH v28 16/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes Casey Schaufler
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, Pablo Neira Ayuso, netdev,
netfilter-devel
Change netlink netfilter interfaces to use lsmcontext
pointers, and remove scaffolding.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
---
net/netfilter/nfnetlink_queue.c | 37 +++++++++++++--------------------
1 file changed, 14 insertions(+), 23 deletions(-)
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index d5cff4559237..cffb04baf7b8 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -301,15 +301,13 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
return -1;
}
-static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
+static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
{
- u32 seclen = 0;
#if IS_ENABLED(CONFIG_NETWORK_SECMARK)
struct lsmblob blob;
- struct lsmcontext context = { };
if (!skb || !sk_fullsock(skb->sk))
- return 0;
+ return;
read_lock_bh(&skb->sk->sk_callback_lock);
@@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
* blob. security_secid_to_secctx() will know which security
* module to use to create the secctx. */
lsmblob_init(&blob, skb->secmark);
- security_secid_to_secctx(&blob, &context);
- *secdata = context.context;
+ security_secid_to_secctx(&blob, context);
}
read_unlock_bh(&skb->sk->sk_callback_lock);
- seclen = context.len;
#endif
- return seclen;
+ return;
}
static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
@@ -397,12 +393,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
struct net_device *indev;
struct net_device *outdev;
struct nf_conn *ct = NULL;
+ struct lsmcontext context = { };
enum ip_conntrack_info ctinfo;
struct nfnl_ct_hook *nfnl_ct;
bool csum_verify;
- struct lsmcontext scaff; /* scaffolding */
- char *secdata = NULL;
- u32 seclen = 0;
size = nlmsg_total_size(sizeof(struct nfgenmsg))
+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
@@ -470,9 +464,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
}
if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
- seclen = nfqnl_get_sk_secctx(entskb, &secdata);
- if (seclen)
- size += nla_total_size(seclen);
+ nfqnl_get_sk_secctx(entskb, &context);
+ if (context.len)
+ size += nla_total_size(context.len);
}
skb = alloc_skb(size, GFP_ATOMIC);
@@ -602,7 +596,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
goto nla_put_failure;
- if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
+ if (context.len &&
+ nla_put(skb, NFQA_SECCTX, context.len, context.context))
goto nla_put_failure;
if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
@@ -630,10 +625,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
}
nlh->nlmsg_len = skb->len;
- if (seclen) {
- lsmcontext_init(&scaff, secdata, seclen, 0);
- security_release_secctx(&scaff);
- }
+ if (context.len)
+ security_release_secctx(&context);
return skb;
nla_put_failure:
@@ -641,10 +634,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
kfree_skb(skb);
net_err_ratelimited("nf_queue: error creating packet message\n");
nlmsg_failure:
- if (seclen) {
- lsmcontext_init(&scaff, secdata, seclen, 0);
- security_release_secctx(&scaff);
- }
+ if (context.len)
+ security_release_secctx(&context);
return NULL;
}
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 19/25] NET: Store LSM netlabel data in a lsmblob
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
` (5 preceding siblings ...)
2021-07-22 0:47 ` [PATCH v28 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes Casey Schaufler
7 siblings, 0 replies; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, netdev
Netlabel uses LSM interfaces requiring an lsmblob and
the internal storage is used to pass information between
these interfaces, so change the internal data from a secid
to a lsmblob. Update the netlabel interfaces and their
callers to accommodate the change. This requires that the
modules using netlabel use the lsm_id.slot to access the
correct secid when using netlabel.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
---
include/net/netlabel.h | 8 +--
net/ipv4/cipso_ipv4.c | 26 ++++++----
net/netlabel/netlabel_kapi.c | 6 +--
net/netlabel/netlabel_unlabeled.c | 79 +++++++++--------------------
net/netlabel/netlabel_unlabeled.h | 2 +-
security/selinux/hooks.c | 2 +-
security/selinux/include/security.h | 1 +
security/selinux/netlabel.c | 2 +-
security/selinux/ss/services.c | 4 +-
security/smack/smack.h | 1 +
security/smack/smack_access.c | 2 +-
security/smack/smack_lsm.c | 11 ++--
security/smack/smackfs.c | 10 ++--
13 files changed, 68 insertions(+), 86 deletions(-)
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 43ae50337685..73fc25b4042b 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -166,7 +166,7 @@ struct netlbl_lsm_catmap {
* @attr.mls: MLS sensitivity label
* @attr.mls.cat: MLS category bitmap
* @attr.mls.lvl: MLS sensitivity level
- * @attr.secid: LSM specific secid token
+ * @attr.lsmblob: LSM specific data
*
* Description:
* This structure is used to pass security attributes between NetLabel and the
@@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
struct netlbl_lsm_catmap *cat;
u32 lvl;
} mls;
- u32 secid;
+ struct lsmblob lsmblob;
} attr;
};
@@ -415,7 +415,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info);
int netlbl_cfg_unlbl_static_del(struct net *net,
const char *dev_name,
@@ -523,7 +523,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
return -ENOSYS;
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 099259fc826a..9bd72ec01785 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
/* Base length of the local tag (non-standard tag).
* Tag definition (may change between kernel versions)
*
- * 0 8 16 24 32
- * +----------+----------+----------+----------+
- * | 10000000 | 00000110 | 32-bit secid value |
- * +----------+----------+----------+----------+
- * | in (host byte order)|
- * +----------+----------+
- *
+ * 0 8 16 16 + sizeof(struct lsmblob)
+ * +----------+----------+---------------------+
+ * | 10000000 | 00000110 | LSM blob data |
+ * +----------+----------+---------------------+
+ *
+ * All secid and flag fields are in host byte order.
+ * The lsmblob structure size varies depending on which
+ * Linux security modules are built in the kernel.
+ * The data is opaque.
*/
-#define CIPSO_V4_TAG_LOC_BLEN 6
+#define CIPSO_V4_TAG_LOC_BLEN (2 + sizeof(struct lsmblob))
/*
* Helper Functions
@@ -1460,7 +1462,11 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
buffer[0] = CIPSO_V4_TAG_LOCAL;
buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
- *(u32 *)&buffer[2] = secattr->attr.secid;
+ /* Ensure that there is sufficient space in the CIPSO header
+ * for the LSM data. */
+ BUILD_BUG_ON(CIPSO_V4_TAG_LOC_BLEN > CIPSO_V4_OPT_LEN_MAX);
+ memcpy(&buffer[2], &secattr->attr.lsmblob,
+ sizeof(secattr->attr.lsmblob));
return CIPSO_V4_TAG_LOC_BLEN;
}
@@ -1480,7 +1486,7 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
const unsigned char *tag,
struct netlbl_lsm_secattr *secattr)
{
- secattr->attr.secid = *(u32 *)&tag[2];
+ memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
secattr->flags |= NETLBL_SECATTR_SECID;
return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index beb0e573266d..158bab993e32 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -196,7 +196,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
* @addr: IP address in network byte order (struct in[6]_addr)
* @mask: address mask in network byte order (struct in[6]_addr)
* @family: address family
- * @secid: LSM secid value for the entry
+ * @lsmblob: LSM data value for the entry
* @audit_info: NetLabel audit information
*
* Description:
@@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
u32 addr_len;
@@ -230,7 +230,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
return netlbl_unlhsh_add(net,
dev_name, addr, mask, addr_len,
- secid, audit_info);
+ lsmblob, audit_info);
}
/**
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 9910d3e9d287..289602835b75 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -66,7 +66,7 @@ struct netlbl_unlhsh_tbl {
#define netlbl_unlhsh_addr4_entry(iter) \
container_of(iter, struct netlbl_unlhsh_addr4, list)
struct netlbl_unlhsh_addr4 {
- u32 secid;
+ struct lsmblob lsmblob;
struct netlbl_af4list list;
struct rcu_head rcu;
@@ -74,7 +74,7 @@ struct netlbl_unlhsh_addr4 {
#define netlbl_unlhsh_addr6_entry(iter) \
container_of(iter, struct netlbl_unlhsh_addr6, list)
struct netlbl_unlhsh_addr6 {
- u32 secid;
+ struct lsmblob lsmblob;
struct netlbl_af6list list;
struct rcu_head rcu;
@@ -220,7 +220,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
* @iface: the associated interface entry
* @addr: IPv4 address in network byte order
* @mask: IPv4 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
*
* Description:
* Add a new address entry into the unlabeled connection hash table using the
@@ -231,7 +231,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
const struct in_addr *addr,
const struct in_addr *mask,
- u32 secid)
+ struct lsmblob *lsmblob)
{
int ret_val;
struct netlbl_unlhsh_addr4 *entry;
@@ -243,7 +243,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
entry->list.addr = addr->s_addr & mask->s_addr;
entry->list.mask = mask->s_addr;
entry->list.valid = 1;
- entry->secid = secid;
+ entry->lsmblob = *lsmblob;
spin_lock(&netlbl_unlhsh_lock);
ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
@@ -260,7 +260,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
* @iface: the associated interface entry
* @addr: IPv6 address in network byte order
* @mask: IPv6 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
*
* Description:
* Add a new address entry into the unlabeled connection hash table using the
@@ -271,7 +271,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
const struct in6_addr *addr,
const struct in6_addr *mask,
- u32 secid)
+ struct lsmblob *lsmblob)
{
int ret_val;
struct netlbl_unlhsh_addr6 *entry;
@@ -287,7 +287,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
entry->list.mask = *mask;
entry->list.valid = 1;
- entry->secid = secid;
+ entry->lsmblob = *lsmblob;
spin_lock(&netlbl_unlhsh_lock);
ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
@@ -366,7 +366,7 @@ int netlbl_unlhsh_add(struct net *net,
const void *addr,
const void *mask,
u32 addr_len,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
int ret_val;
@@ -375,7 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
struct netlbl_unlhsh_iface *iface;
struct audit_buffer *audit_buf = NULL;
struct lsmcontext context;
- struct lsmblob blob;
if (addr_len != sizeof(struct in_addr) &&
addr_len != sizeof(struct in6_addr))
@@ -408,7 +407,7 @@ int netlbl_unlhsh_add(struct net *net,
const struct in_addr *addr4 = addr;
const struct in_addr *mask4 = mask;
- ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
+ ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
if (audit_buf != NULL)
netlbl_af4list_audit_addr(audit_buf, 1,
dev_name,
@@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
const struct in6_addr *addr6 = addr;
const struct in6_addr *mask6 = mask;
- ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
+ ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
if (audit_buf != NULL)
netlbl_af6list_audit_addr(audit_buf, 1,
dev_name,
@@ -438,11 +437,7 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- /* lsmblob_init() puts secid into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, secid);
- if (security_secid_to_secctx(&blob, &context) == 0) {
+ if (security_secid_to_secctx(lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -477,7 +472,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -497,13 +491,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
addr->s_addr, mask->s_addr);
if (dev != NULL)
dev_put(dev);
- /* lsmblob_init() puts entry->secid into all of the secids
- * in blob. security_secid_to_secctx() will know which
- * security module to use to create the secctx. */
- if (entry != NULL)
- lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -544,7 +533,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- struct lsmblob blob;
spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -563,13 +551,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
addr, mask);
if (dev != NULL)
dev_put(dev);
- /* lsmblob_init() puts entry->secid into all of the secids
- * in blob. security_secid_to_secctx() will know which
- * security module to use to create the secctx. */
- if (entry != NULL)
- lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -923,14 +906,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
if (ret_val != 0)
return ret_val;
- /* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
- * instead of a u32 later in this patch set. security_secctx_to_secid()
- * will only be setting one entry in the lsmblob struct, so it is
- * safe to use lsmblob_value() to get that one value. */
-
- return netlbl_unlhsh_add(&init_net,
- dev_name, addr, mask, addr_len,
- lsmblob_value(&blob), &audit_info);
+ return netlbl_unlhsh_add(&init_net, dev_name, addr, mask, addr_len,
+ &blob, &audit_info);
}
/**
@@ -977,11 +954,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
if (ret_val != 0)
return ret_val;
- /* security_secctx_to_secid() will only put one secid into the lsmblob
- * so it's safe to use lsmblob_value() to get the secid. */
- return netlbl_unlhsh_add(&init_net,
- NULL, addr, mask, addr_len,
- lsmblob_value(&blob), &audit_info);
+ return netlbl_unlhsh_add(&init_net, NULL, addr, mask, addr_len, &blob,
+ &audit_info);
}
/**
@@ -1093,8 +1067,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
struct net_device *dev;
struct lsmcontext context;
void *data;
- u32 secid;
- struct lsmblob blob;
+ struct lsmblob *lsmb;
data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1132,7 +1105,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
if (ret_val != 0)
goto list_cb_failure;
- secid = addr4->secid;
+ lsmb = (struct lsmblob *)&addr4->lsmblob;
} else {
ret_val = nla_put_in6_addr(cb_arg->skb,
NLBL_UNLABEL_A_IPV6ADDR,
@@ -1146,14 +1119,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
if (ret_val != 0)
goto list_cb_failure;
- secid = addr6->secid;
+ lsmb = (struct lsmblob *)&addr6->lsmblob;
}
- /* lsmblob_init() secid into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, secid);
- ret_val = security_secid_to_secctx(&blob, &context);
+ ret_val = security_secid_to_secctx(lsmb, &context);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
@@ -1512,7 +1481,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
&iface->addr4_list);
if (addr4 == NULL)
goto unlabel_getattr_nolabel;
- secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
+ secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
break;
}
#if IS_ENABLED(CONFIG_IPV6)
@@ -1525,7 +1494,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
&iface->addr6_list);
if (addr6 == NULL)
goto unlabel_getattr_nolabel;
- secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
+ secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
break;
}
#endif /* IPv6 */
diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
index 058e3a285d56..168920780994 100644
--- a/net/netlabel/netlabel_unlabeled.h
+++ b/net/netlabel/netlabel_unlabeled.h
@@ -211,7 +211,7 @@ int netlbl_unlhsh_add(struct net *net,
const void *addr,
const void *mask,
u32 addr_len,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info);
int netlbl_unlhsh_remove(struct net *net,
const char *dev_name,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3b95eb39a3bf..12ae311b7275 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7112,7 +7112,7 @@ static int selinux_perf_event_write(struct perf_event *event)
}
#endif
-static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+struct lsm_id selinux_lsmid __lsm_ro_after_init = {
.lsm = "selinux",
.slot = LSMBLOB_NEEDED
};
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index ac0ece01305a..9f856f2cd277 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -73,6 +73,7 @@
struct netlbl_lsm_secattr;
extern int selinux_enabled_boot;
+extern struct lsm_id selinux_lsmid;
/*
* type_datum properties
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 6a94b31b5472..d8d7603ab14e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -108,7 +108,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
return NULL;
if ((secattr->flags & NETLBL_SECATTR_SECID) &&
- (secattr->attr.secid == sid))
+ (secattr->attr.lsmblob.secid[selinux_lsmid.slot] == sid))
return secattr;
return NULL;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index d84c77f370dc..f6be8cd7666b 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3899,7 +3899,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
if (secattr->flags & NETLBL_SECATTR_CACHE)
*sid = *(u32 *)secattr->cache->data;
else if (secattr->flags & NETLBL_SECATTR_SECID)
- *sid = secattr->attr.secid;
+ *sid = secattr->attr.lsmblob.secid[selinux_lsmid.slot];
else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
rc = -EIDRM;
ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
@@ -3977,7 +3977,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
if (secattr->domain == NULL)
goto out;
- secattr->attr.secid = sid;
+ secattr->attr.lsmblob.secid[selinux_lsmid.slot] = sid;
secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
mls_export_netlbl_lvl(policydb, ctx, secattr);
rc = mls_export_netlbl_cat(policydb, ctx, secattr);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index b5bdf947792f..0eaae6b3f935 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -303,6 +303,7 @@ int smack_populate_secattr(struct smack_known *skp);
* Shared data.
*/
extern int smack_enabled;
+extern struct lsm_id smack_lsmid;
extern int smack_cipso_direct;
extern int smack_cipso_mapped;
extern struct smack_known *smack_net_ambient;
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 1f391f6a3d47..ceea74bbaedc 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -525,7 +525,7 @@ int smack_populate_secattr(struct smack_known *skp)
{
int slen;
- skp->smk_netlabel.attr.secid = skp->smk_secid;
+ skp->smk_netlabel.attr.lsmblob.secid[smack_lsmid.slot] = skp->smk_secid;
skp->smk_netlabel.domain = skp->smk_known;
skp->smk_netlabel.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
if (skp->smk_netlabel.cache != NULL) {
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7aa7ea38f627..e65497a5c095 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3720,11 +3720,12 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
return (struct smack_known *)sap->cache->data;
+ /*
+ * Looks like a fallback, which gives us a secid.
+ */
if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
- /*
- * Looks like a fallback, which gives us a secid.
- */
- return smack_from_secid(sap->attr.secid);
+ return smack_from_secid(
+ sap->attr.lsmblob.secid[smack_lsmid.slot]);
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
/*
@@ -4701,7 +4702,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_superblock = sizeof(struct superblock_smack),
};
-static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+struct lsm_id smack_lsmid __lsm_ro_after_init = {
.lsm = "smack",
.slot = LSMBLOB_NEEDED
};
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 3a75d2a8f517..9cda52f2ec31 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1142,6 +1142,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
+ struct lsmblob lsmblob;
struct smk_net4addr *snp;
struct sockaddr_in newname;
char *smack;
@@ -1273,10 +1274,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
* this host so that incoming packets get labeled.
* but only if we didn't get the special CIPSO option
*/
- if (rc == 0 && skp != NULL)
+ if (rc == 0 && skp != NULL) {
+ lsmblob_init(&lsmblob, 0);
+ lsmblob.secid[smack_lsmid.slot] = snp->smk_label->smk_secid;
rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
- &snp->smk_host, &snp->smk_mask, PF_INET,
- snp->smk_label->smk_secid, &audit_info);
+ &snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
+ &audit_info);
+ }
if (rc == 0)
rc = count;
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
[not found] <20210722004758.12371-1-casey@schaufler-ca.com>
` (6 preceding siblings ...)
2021-07-22 0:47 ` [PATCH v28 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
@ 2021-07-22 0:47 ` Casey Schaufler
2021-08-12 20:59 ` Paul Moore
7 siblings, 1 reply; 15+ messages in thread
From: Casey Schaufler @ 2021-07-22 0:47 UTC (permalink / raw)
To: casey.schaufler, jmorris, linux-security-module, selinux
Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel,
paul, sds, linux-kernel, netdev
Create a new audit record type to contain the subject information
when there are multiple security modules that require such data.
This record is linked with the same timestamp and serial number
using the audit_alloc_local() mechanism.
The record is produced only in cases where there is more than one
security module with a process "context".
In cases where this record is produced the subj= fields of
other records in the audit event will be set to "subj=?".
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor="=unconfined"
subj_smack="_"
There will be a subj_$LSM= entry for each security module
LSM that supports the secid_to_secctx and secctx_to_secid
hooks. The BPF security module implements secid/secctx
translation hooks, so it has to be considered to provide a
secctx even though it may not actually do so.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
To: paul@paul-moore.com
To: linux-audit@redhat.com
To: rgb@redhat.com
Cc: netdev@vger.kernel.org
---
drivers/android/binder.c | 2 +-
include/linux/audit.h | 16 +++++
include/linux/security.h | 16 ++++-
include/net/netlabel.h | 2 +-
include/net/scm.h | 2 +-
include/net/xfrm.h | 13 +++-
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 90 +++++++++++++++++++------
kernel/auditfilter.c | 5 +-
kernel/auditsc.c | 27 ++++++--
net/ipv4/ip_sockglue.c | 2 +-
net/netfilter/nf_conntrack_netlink.c | 4 +-
net/netfilter/nf_conntrack_standalone.c | 2 +-
net/netfilter/nfnetlink_queue.c | 2 +-
net/netlabel/netlabel_unlabeled.c | 21 +++---
net/netlabel/netlabel_user.c | 14 ++--
net/netlabel/netlabel_user.h | 6 +-
net/xfrm/xfrm_policy.c | 8 ++-
net/xfrm/xfrm_state.c | 18 +++--
security/integrity/ima/ima_api.c | 6 +-
security/integrity/integrity_audit.c | 5 +-
security/security.c | 46 ++++++++-----
security/smack/smackfs.c | 3 +-
23 files changed, 221 insertions(+), 90 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 2c3a2348a144..3520caa0260c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2722,7 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
* case well anyway.
*/
security_task_getsecid_obj(proc->tsk, &blob);
- ret = security_secid_to_secctx(&blob, &lsmctx);
+ ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY);
if (ret) {
return_error = BR_FAILED_REPLY;
return_error_param = ret;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 97cd7471e572..85eb87f6f92d 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -291,6 +291,7 @@ extern int audit_alloc(struct task_struct *task);
extern void __audit_free(struct task_struct *task);
extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
extern void audit_free_context(struct audit_context *context);
+extern void audit_free_local(struct audit_context *context);
extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
unsigned long a2, unsigned long a3);
extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -386,6 +387,19 @@ static inline void audit_ptrace(struct task_struct *t)
__audit_ptrace(t);
}
+static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp)
+{
+ struct audit_context *context = audit_context();
+
+ if (context)
+ return context;
+
+ if (lsm_multiple_contexts())
+ return audit_alloc_local(gfp);
+
+ return NULL;
+}
+
/* Private API (for audit.c only) */
extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
@@ -560,6 +574,8 @@ extern int audit_signals;
}
static inline void audit_free_context(struct audit_context *context)
{ }
+static inline void audit_free_local(struct audit_context *context)
+{ }
static inline int audit_alloc(struct task_struct *task)
{
return 0;
diff --git a/include/linux/security.h b/include/linux/security.h
index 3e9743118fb9..b3cf68cf2bd6 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -182,6 +182,8 @@ struct lsmblob {
#define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */
#define LSMBLOB_NEEDED -2 /* Slot requested on initialization */
#define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */
+#define LSMBLOB_DISPLAY -4 /* Use the "display" slot */
+#define LSMBLOB_FIRST -5 /* Use the default "display" slot */
/**
* lsmblob_init - initialize an lsmblob structure
@@ -248,6 +250,15 @@ static inline u32 lsmblob_value(const struct lsmblob *blob)
return 0;
}
+static inline bool lsm_multiple_contexts(void)
+{
+#ifdef CONFIG_SECURITY
+ return lsm_slot_to_name(1) != NULL;
+#else
+ return false;
+#endif
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
@@ -578,7 +589,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+ int display);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
void security_release_secctx(struct lsmcontext *cp);
@@ -1433,7 +1445,7 @@ static inline int security_ismaclabel(const char *name)
}
static inline int security_secid_to_secctx(struct lsmblob *blob,
- struct lsmcontext *cp)
+ struct lsmcontext *cp, int display)
{
return -EOPNOTSUPP;
}
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 73fc25b4042b..216cb1ffc8f0 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -97,7 +97,7 @@ struct calipso_doi;
/* NetLabel audit information */
struct netlbl_audit {
- u32 secid;
+ struct lsmblob lsmdata;
kuid_t loginuid;
unsigned int sessionid;
};
diff --git a/include/net/scm.h b/include/net/scm.h
index b77a52f93389..f4d567d4885e 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
* and the infrastructure will know which it is.
*/
lsmblob_init(&lb, scm->secid);
- err = security_secid_to_secctx(&lb, &context);
+ err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
if (!err) {
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index cbff7c2a9724..a10fa01f7bf4 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -660,13 +660,22 @@ struct xfrm_spi_skb_cb {
#define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
#ifdef CONFIG_AUDITSYSCALL
-static inline struct audit_buffer *xfrm_audit_start(const char *op)
+static inline struct audit_buffer *xfrm_audit_start(const char *op,
+ struct audit_context **lac)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf = NULL;
if (audit_enabled == AUDIT_OFF)
return NULL;
- audit_buf = audit_log_start(audit_context(), GFP_ATOMIC,
+ context = audit_context();
+ if (lac != NULL) {
+ if (lsm_multiple_contexts() && context == NULL)
+ context = audit_alloc_local(GFP_ATOMIC);
+ *lac = context;
+ }
+
+ audit_buf = audit_log_start(context, GFP_ATOMIC,
AUDIT_MAC_IPSEC_EVENT);
if (audit_buf == NULL)
return NULL;
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index daa481729e9b..4432a8bed8e0 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -139,6 +139,7 @@
#define AUDIT_MAC_UNLBL_STCDEL 1417 /* NetLabel: del a static label */
#define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */
#define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */
+#define AUDIT_MAC_TASK_CONTEXTS 1420 /* Multiple LSM contexts */
#define AUDIT_FIRST_KERN_ANOM_MSG 1700
#define AUDIT_LAST_KERN_ANOM_MSG 1799
diff --git a/kernel/audit.c b/kernel/audit.c
index 841123390d41..cba63789a164 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -386,10 +386,12 @@ void audit_log_lost(const char *message)
static int audit_log_config_change(char *function_name, u32 new, u32 old,
int allow_changes)
{
+ struct audit_context *context;
struct audit_buffer *ab;
int rc = 0;
- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
if (unlikely(!ab))
return rc;
audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
@@ -399,6 +401,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old,
allow_changes = 0; /* Something weird, deny request */
audit_log_format(ab, " res=%d", allow_changes);
audit_log_end(ab);
+ audit_free_local(context);
return rc;
}
@@ -1072,12 +1075,6 @@ static void audit_log_common_recv_msg(struct audit_context *context,
audit_log_task_context(*ab);
}
-static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
- u16 msg_type)
-{
- audit_log_common_recv_msg(NULL, ab, msg_type);
-}
-
int is_audit_feature_set(int i)
{
return af.features & AUDIT_FEATURE_TO_MASK(i);
@@ -1190,6 +1187,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
struct audit_sig_info *sig_data;
+ struct audit_context *lcontext;
err = audit_netlink_ok(skb, msg_type);
if (err)
@@ -1357,7 +1355,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (err)
break;
}
- audit_log_user_recv_msg(&ab, msg_type);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, msg_type);
if (msg_type != AUDIT_USER_TTY) {
/* ensure NULL termination */
str[data_len - 1] = '\0';
@@ -1371,6 +1370,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
audit_log_n_untrustedstring(ab, str, data_len);
}
audit_log_end(ab);
+ audit_free_local(lcontext);
}
break;
case AUDIT_ADD_RULE:
@@ -1378,13 +1378,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (data_len < sizeof(struct audit_rule_data))
return -EINVAL;
if (audit_enabled == AUDIT_LOCKED) {
- audit_log_common_recv_msg(audit_context(), &ab,
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab,
AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=%s audit_enabled=%d res=0",
msg_type == AUDIT_ADD_RULE ?
"add_rule" : "remove_rule",
audit_enabled);
audit_log_end(ab);
+ audit_free_local(lcontext);
return -EPERM;
}
err = audit_rule_change(msg_type, seq, data, data_len);
@@ -1394,10 +1396,11 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
break;
case AUDIT_TRIM:
audit_trim_trees();
- audit_log_common_recv_msg(audit_context(), &ab,
- AUDIT_CONFIG_CHANGE);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=trim res=1");
audit_log_end(ab);
+ audit_free_local(lcontext);
break;
case AUDIT_MAKE_EQUIV: {
void *bufp = data;
@@ -1425,14 +1428,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
/* OK, here comes... */
err = audit_tag_tree(old, new);
- audit_log_common_recv_msg(audit_context(), &ab,
- AUDIT_CONFIG_CHANGE);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=make_equiv old=");
audit_log_untrustedstring(ab, old);
audit_log_format(ab, " new=");
audit_log_untrustedstring(ab, new);
audit_log_format(ab, " res=%d", !err);
audit_log_end(ab);
+ audit_free_local(lcontext);
kfree(old);
kfree(new);
break;
@@ -1443,7 +1447,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (lsmblob_is_set(&audit_sig_lsm)) {
err = security_secid_to_secctx(&audit_sig_lsm,
- &context);
+ &context, LSMBLOB_FIRST);
if (err)
return err;
}
@@ -1498,13 +1502,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
old.enabled = t & AUDIT_TTY_ENABLE;
old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
- audit_log_common_recv_msg(audit_context(), &ab,
- AUDIT_CONFIG_CHANGE);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
" old-log_passwd=%d new-log_passwd=%d res=%d",
old.enabled, s.enabled, old.log_passwd,
s.log_passwd, !err);
audit_log_end(ab);
+ audit_free_local(lcontext);
break;
}
default:
@@ -1550,6 +1555,7 @@ static void audit_receive(struct sk_buff *skb)
/* Log information about who is connecting to the audit multicast socket */
static void audit_log_multicast(int group, const char *op, int err)
{
+ struct audit_context *context;
const struct cred *cred;
struct tty_struct *tty;
char comm[sizeof(current->comm)];
@@ -1558,7 +1564,8 @@ static void audit_log_multicast(int group, const char *op, int err)
if (!audit_enabled)
return;
- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_EVENT_LISTENER);
if (!ab)
return;
@@ -1577,6 +1584,7 @@ static void audit_log_multicast(int group, const char *op, int err)
audit_log_d_path_exe(ab, current->mm); /* exe= */
audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
audit_log_end(ab);
+ audit_free_local(context);
}
/* Run custom bind function on netlink socket group connect or bind requests. */
@@ -2128,6 +2136,36 @@ void audit_log_key(struct audit_buffer *ab, char *key)
audit_log_format(ab, "(null)");
}
+static void audit_log_lsm(struct audit_context *context, struct lsmblob *blob)
+{
+ struct audit_buffer *ab;
+ struct lsmcontext lsmdata;
+ bool sep = false;
+ int error;
+ int i;
+
+ ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS);
+ if (!ab)
+ return; /* audit_panic or being filtered */
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+ if (blob->secid[i] == 0)
+ continue;
+ error = security_secid_to_secctx(blob, &lsmdata, i);
+ if (error && error != -EINVAL) {
+ audit_panic("error in audit_log_lsm");
+ return;
+ }
+
+ audit_log_format(ab, "%ssubj_%s=\"%s\"", sep ? " " : "",
+ lsm_slot_to_name(i), lsmdata.context);
+ sep = true;
+
+ security_release_secctx(&lsmdata);
+ }
+ audit_log_end(ab);
+}
+
int audit_log_task_context(struct audit_buffer *ab)
{
int error;
@@ -2138,7 +2176,18 @@ int audit_log_task_context(struct audit_buffer *ab)
if (!lsmblob_is_set(&blob))
return 0;
- error = security_secid_to_secctx(&blob, &context);
+ /*
+ * If there is more than one security module that has a
+ * subject "context" it's necessary to put the subject data
+ * into a separate record to maintain compatibility.
+ */
+ if (lsm_multiple_contexts()) {
+ audit_log_format(ab, " subj=?");
+ audit_log_lsm(ab->ctx, &blob);
+ return 0;
+ }
+
+ error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
if (error) {
if (error != -EINVAL)
goto error_path;
@@ -2274,6 +2323,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
unsigned int oldsessionid,
unsigned int sessionid, int rc)
{
+ struct audit_context *context;
struct audit_buffer *ab;
uid_t uid, oldloginuid, loginuid;
struct tty_struct *tty;
@@ -2281,7 +2331,8 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
if (!audit_enabled)
return;
- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_LOGIN);
if (!ab)
return;
@@ -2297,6 +2348,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
oldsessionid, sessionid, !rc);
audit_put_tty(tty);
audit_log_end(ab);
+ audit_free_local(context);
}
/**
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 1ba14a7a38f7..fd71c6bac200 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1098,12 +1098,14 @@ static void audit_list_rules(int seq, struct sk_buff_head *q)
/* Log rule additions and removals */
static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
{
+ struct audit_context *context;
struct audit_buffer *ab;
if (!audit_enabled)
return;
- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
if (!ab)
return;
audit_log_session_info(ab);
@@ -1112,6 +1114,7 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re
audit_log_key(ab, rule->filterkey);
audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
audit_log_end(ab);
+ audit_free_local(context);
}
/**
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0e58a3ab56f5..01fdcbf468c0 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -993,12 +993,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags)
context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
if (!context) {
audit_log_lost("out of memory in audit_alloc_local");
- goto out;
+ return NULL;
}
context->serial = audit_serial();
ktime_get_coarse_real_ts64(&context->ctime);
context->local = true;
-out:
return context;
}
EXPORT_SYMBOL(audit_alloc_local);
@@ -1019,6 +1018,13 @@ void audit_free_context(struct audit_context *context)
}
EXPORT_SYMBOL(audit_free_context);
+void audit_free_local(struct audit_context *context)
+{
+ if (context && context->local)
+ audit_free_context(context);
+}
+EXPORT_SYMBOL(audit_free_local);
+
static int audit_log_pid_context(struct audit_context *context, pid_t pid,
kuid_t auid, kuid_t uid,
unsigned int sessionid,
@@ -1036,7 +1042,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (lsmblob_is_set(blob)) {
- if (security_secid_to_secctx(blob, &lsmctx)) {
+ if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
@@ -1282,7 +1288,8 @@ static void show_special(struct audit_context *context, int *call_panic)
struct lsmblob blob;
lsmblob_init(&blob, osid);
- if (security_secid_to_secctx(&blob, &lsmcxt)) {
+ if (security_secid_to_secctx(&blob, &lsmcxt,
+ LSMBLOB_FIRST)) {
audit_log_format(ab, " osid=%u", osid);
*call_panic = 1;
} else {
@@ -1439,7 +1446,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
struct lsmcontext lsmctx;
lsmblob_init(&blob, n->osid);
- if (security_secid_to_secctx(&blob, &lsmctx)) {
+ if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
audit_log_format(ab, " osid=%u", n->osid);
if (call_panic)
*call_panic = 2;
@@ -2637,10 +2644,12 @@ void __audit_ntp_log(const struct audit_ntp_data *ad)
void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
enum audit_nfcfgop op, gfp_t gfp)
{
+ struct audit_context *context;
struct audit_buffer *ab;
char comm[sizeof(current->comm)];
- ab = audit_log_start(audit_context(), gfp, AUDIT_NETFILTER_CFG);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, gfp, AUDIT_NETFILTER_CFG);
if (!ab)
return;
audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
@@ -2651,6 +2660,7 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
audit_log_format(ab, " comm=");
audit_log_untrustedstring(ab, get_task_comm(comm, current));
audit_log_end(ab);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
@@ -2685,6 +2695,7 @@ static void audit_log_task(struct audit_buffer *ab)
*/
void audit_core_dumps(long signr)
{
+ struct audit_context *context;
struct audit_buffer *ab;
if (!audit_enabled)
@@ -2693,12 +2704,14 @@ void audit_core_dumps(long signr)
if (signr == SIGQUIT) /* don't care for those */
return;
- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_ABEND);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_ANOM_ABEND);
if (unlikely(!ab))
return;
audit_log_task(ab);
audit_log_format(ab, " sig=%ld res=1", signr);
audit_log_end(ab);
+ audit_free_local(context);
}
/**
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ae073b642fa7..5c0029a3a595 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -140,7 +140,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
return;
lsmblob_init(&lb, secid);
- err = security_secid_to_secctx(&lb, &context);
+ err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
if (err)
return;
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 668b31ecd638..05bdbb942499 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -347,7 +347,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &context);
+ ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
if (ret)
return 0;
@@ -658,7 +658,7 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
struct lsmblob blob;
struct lsmcontext context;
- ret = security_secid_to_secctx(&blob, &context);
+ ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
if (ret)
return 0;
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index b5796a8e5e90..3da3770e9739 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -177,7 +177,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
struct lsmcontext context;
lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &context);
+ ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
if (ret)
return;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index cffb04baf7b8..9bef0bddf7d6 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -316,7 +316,7 @@ static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
* blob. security_secid_to_secctx() will know which security
* module to use to create the secctx. */
lsmblob_init(&blob, skb->secmark);
- security_secid_to_secctx(&blob, context);
+ security_secid_to_secctx(&blob, context, LSMBLOB_DISPLAY);
}
read_unlock_bh(&skb->sk->sk_callback_lock);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 289602835b75..245f63f5773a 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -437,7 +437,8 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- if (security_secid_to_secctx(lsmblob, &context) == 0) {
+ if (security_secid_to_secctx(lsmblob, &context,
+ LSMBLOB_FIRST) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -492,7 +493,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
if (dev != NULL)
dev_put(dev);
if (entry != NULL &&
- security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context,
+ LSMBLOB_FIRST) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -552,7 +554,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
if (dev != NULL)
dev_put(dev);
if (entry != NULL &&
- security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context,
+ LSMBLOB_FIRST) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -738,11 +741,10 @@ static void netlbl_unlabel_acceptflg_set(u8 value,
netlabel_unlabel_acceptflg = value;
audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
audit_info);
- if (audit_buf != NULL) {
+ if (audit_buf != NULL)
audit_log_format(audit_buf,
" unlbl_accept=%u old=%u", value, old_val);
- audit_log_end(audit_buf);
- }
+ audit_log_end(audit_buf);
}
/**
@@ -1122,7 +1124,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
lsmb = (struct lsmblob *)&addr6->lsmblob;
}
- ret_val = security_secid_to_secctx(lsmb, &context);
+ ret_val = security_secid_to_secctx(lsmb, &context, LSMBLOB_FIRST);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
@@ -1528,14 +1530,11 @@ int __init netlbl_unlabel_defconf(void)
int ret_val;
struct netlbl_dom_map *entry;
struct netlbl_audit audit_info;
- struct lsmblob blob;
/* Only the kernel is allowed to call this function and the only time
* it is called is at bootup before the audit subsystem is reporting
* messages so don't worry to much about these values. */
- security_task_getsecid_subj(current, &blob);
- /* scaffolding until audit_info.secid is converted */
- audit_info.secid = blob.secid[0];
+ security_task_getsecid_subj(current, &audit_info.lsmdata);
audit_info.loginuid = GLOBAL_ROOT_UID;
audit_info.sessionid = 0;
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 951ba0639d20..9c43c3cb2088 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,7 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
{
struct audit_buffer *audit_buf;
struct lsmcontext context;
- struct lsmblob blob;
if (audit_enabled == AUDIT_OFF)
return NULL;
@@ -98,11 +97,14 @@ struct audit_buffer *netlbl_audit_start_common(int type,
from_kuid(&init_user_ns, audit_info->loginuid),
audit_info->sessionid);
- lsmblob_init(&blob, audit_info->secid);
- if (audit_info->secid != 0 &&
- security_secid_to_secctx(&blob, &context) == 0) {
- audit_log_format(audit_buf, " subj=%s", context.context);
- security_release_secctx(&context);
+ if (lsmblob_is_set(&audit_info->lsmdata)) {
+ if (!lsm_multiple_contexts() &&
+ security_secid_to_secctx(&audit_info->lsmdata, &context,
+ LSMBLOB_FIRST) == 0) {
+ audit_log_format(audit_buf, " subj=%s",
+ context.context);
+ security_release_secctx(&context);
+ }
}
return audit_buf;
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index aa31f7bf79ee..e5b15ad41df7 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -32,11 +32,7 @@
*/
static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info)
{
- struct lsmblob blob;
-
- security_task_getsecid_subj(current, &blob);
- /* scaffolding until secid is converted */
- audit_info->secid = blob.secid[0];
+ security_task_getsecid_subj(current, &audit_info->lsmdata);
audit_info->loginuid = audit_get_loginuid(current);
audit_info->sessionid = audit_get_sessionid(current);
}
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 827d84255021..2152e319951d 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -4178,30 +4178,34 @@ static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;
- audit_buf = xfrm_audit_start("SPD-add");
+ audit_buf = xfrm_audit_start("SPD-add", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
xfrm_audit_common_policyinfo(xp, audit_buf);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;
- audit_buf = xfrm_audit_start("SPD-delete");
+ audit_buf = xfrm_audit_start("SPD-delete", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
xfrm_audit_common_policyinfo(xp, audit_buf);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
#endif
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index a2f4001221d1..4d174f42eb60 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2796,29 +2796,33 @@ static void xfrm_audit_helper_pktinfo(struct sk_buff *skb, u16 family,
void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;
- audit_buf = xfrm_audit_start("SAD-add");
+ audit_buf = xfrm_audit_start("SAD-add", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
xfrm_audit_helper_sainfo(x, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_add);
void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;
- audit_buf = xfrm_audit_start("SAD-delete");
+ audit_buf = xfrm_audit_start("SAD-delete", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
xfrm_audit_helper_sainfo(x, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_delete);
@@ -2828,7 +2832,7 @@ void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
struct audit_buffer *audit_buf;
u32 spi;
- audit_buf = xfrm_audit_start("SA-replay-overflow");
+ audit_buf = xfrm_audit_start("SA-replay-overflow", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2846,7 +2850,7 @@ void xfrm_audit_state_replay(struct xfrm_state *x,
struct audit_buffer *audit_buf;
u32 spi;
- audit_buf = xfrm_audit_start("SA-replayed-pkt");
+ audit_buf = xfrm_audit_start("SA-replayed-pkt", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2861,7 +2865,7 @@ void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family)
{
struct audit_buffer *audit_buf;
- audit_buf = xfrm_audit_start("SA-notfound");
+ audit_buf = xfrm_audit_start("SA-notfound", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2875,7 +2879,7 @@ void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
struct audit_buffer *audit_buf;
u32 spi;
- audit_buf = xfrm_audit_start("SA-notfound");
+ audit_buf = xfrm_audit_start("SA-notfound", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2893,7 +2897,7 @@ void xfrm_audit_state_icvfail(struct xfrm_state *x,
__be32 net_spi;
__be32 net_seq;
- audit_buf = xfrm_audit_start("SA-icv-failure");
+ audit_buf = xfrm_audit_start("SA-icv-failure", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 691f68d478f1..3481990a25a6 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -342,6 +342,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename)
{
+ struct audit_context *context;
struct audit_buffer *ab;
char *hash;
const char *algo_name = hash_algo_name[iint->ima_hash->algo];
@@ -358,8 +359,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]);
hash[i * 2] = '\0';
- ab = audit_log_start(audit_context(), GFP_KERNEL,
- AUDIT_INTEGRITY_RULE);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
if (!ab)
goto out;
@@ -369,6 +370,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
audit_log_task_info(ab);
audit_log_end(ab);
+ audit_free_local(context);
iint->flags |= IMA_AUDITED;
out:
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 29220056207f..c3b313886e15 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -38,13 +38,15 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
const char *cause, int result, int audit_info,
int errno)
{
+ struct audit_context *context;
struct audit_buffer *ab;
char name[TASK_COMM_LEN];
if (!integrity_audit_info && audit_info == 1) /* Skip info messages */
return;
- ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, audit_msgno);
audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u",
task_pid_nr(current),
from_kuid(&init_user_ns, current_uid()),
@@ -64,4 +66,5 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
}
audit_log_format(ab, " res=%d errno=%d", !result, errno);
audit_log_end(ab);
+ audit_free_local(context);
}
diff --git a/security/security.c b/security/security.c
index cb359e185d1a..5d7fd982f84a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2309,7 +2309,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
list) {
rc = hp->hook.setprocattr(name, value, size);
- if (rc < 0)
+ if (rc < 0 && rc != -EINVAL)
return rc;
}
@@ -2354,13 +2354,31 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);
-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+ int ilsm)
{
struct security_hook_list *hp;
- int ilsm = lsm_task_ilsm(current);
memset(cp, 0, sizeof(*cp));
+ /*
+ * ilsm either is the slot number use for formatting
+ * or an instruction on which relative slot to use.
+ */
+ if (ilsm == LSMBLOB_DISPLAY)
+ ilsm = lsm_task_ilsm(current);
+ else if (ilsm == LSMBLOB_FIRST)
+ ilsm = LSMBLOB_INVALID;
+ else if (ilsm < 0) {
+ WARN_ONCE(true,
+ "LSM: %s unknown interface LSM\n", __func__);
+ ilsm = LSMBLOB_INVALID;
+ } else if (ilsm >= lsm_slot) {
+ WARN_ONCE(true,
+ "LSM: %s invalid interface LSM\n", __func__);
+ ilsm = LSMBLOB_INVALID;
+ }
+
hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
@@ -2390,7 +2408,7 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
return hp->hook.secctx_to_secid(secdata, seclen,
&blob->secid[hp->lsmid->slot]);
}
- return 0;
+ return -EOPNOTSUPP;
}
EXPORT_SYMBOL(security_secctx_to_secid);
@@ -2884,23 +2902,17 @@ int security_key_getsecurity(struct key *key, char **_buffer)
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
{
struct security_hook_list *hp;
- bool one_is_good = false;
- int rc = 0;
- int trc;
+ int ilsm = lsm_task_ilsm(current);
hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- trc = hp->hook.audit_rule_init(field, op, rulestr,
- &lsmrule[hp->lsmid->slot]);
- if (trc == 0)
- one_is_good = true;
- else
- rc = trc;
+ if (ilsm != LSMBLOB_INVALID && ilsm != hp->lsmid->slot)
+ continue;
+ return hp->hook.audit_rule_init(field, op, rulestr,
+ &lsmrule[hp->lsmid->slot]);
}
- if (one_is_good)
- return 0;
- return rc;
+ return 0;
}
int security_audit_rule_known(struct audit_krule *krule)
@@ -2932,6 +2944,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
continue;
if (lsmrule[hp->lsmid->slot] == NULL)
continue;
+ if (lsmrule[hp->lsmid->slot] == NULL)
+ continue;
rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
field, op,
&lsmrule[hp->lsmid->slot]);
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 9cda52f2ec31..2f0f412fc403 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -185,7 +185,8 @@ static void smk_netlabel_audit_set(struct netlbl_audit *nap)
nap->loginuid = audit_get_loginuid(current);
nap->sessionid = audit_get_sessionid(current);
- nap->secid = skp->smk_secid;
+ lsmblob_init(&nap->lsmdata, 0);
+ nap->lsmdata.secid[smack_lsmid.slot] = skp->smk_secid;
}
/*
--
2.31.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-07-22 0:47 ` [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes Casey Schaufler
@ 2021-08-12 20:59 ` Paul Moore
2021-08-12 22:38 ` Casey Schaufler
0 siblings, 1 reply; 15+ messages in thread
From: Paul Moore @ 2021-08-12 20:59 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev
On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>
> Create a new audit record type to contain the subject information
> when there are multiple security modules that require such data.
> This record is linked with the same timestamp and serial number
> using the audit_alloc_local() mechanism.
> The record is produced only in cases where there is more than one
> security module with a process "context".
> In cases where this record is produced the subj= fields of
> other records in the audit event will be set to "subj=?".
>
> An example of the MAC_TASK_CONTEXTS (1420) record is:
>
> type=UNKNOWN[1420]
> msg=audit(1600880931.832:113)
> subj_apparmor="=unconfined"
> subj_smack="_"
>
> There will be a subj_$LSM= entry for each security module
> LSM that supports the secid_to_secctx and secctx_to_secid
> hooks. The BPF security module implements secid/secctx
> translation hooks, so it has to be considered to provide a
> secctx even though it may not actually do so.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> To: paul@paul-moore.com
> To: linux-audit@redhat.com
> To: rgb@redhat.com
> Cc: netdev@vger.kernel.org
> ---
> drivers/android/binder.c | 2 +-
> include/linux/audit.h | 16 +++++
> include/linux/security.h | 16 ++++-
> include/net/netlabel.h | 2 +-
> include/net/scm.h | 2 +-
> include/net/xfrm.h | 13 +++-
> include/uapi/linux/audit.h | 1 +
> kernel/audit.c | 90 +++++++++++++++++++------
> kernel/auditfilter.c | 5 +-
> kernel/auditsc.c | 27 ++++++--
> net/ipv4/ip_sockglue.c | 2 +-
> net/netfilter/nf_conntrack_netlink.c | 4 +-
> net/netfilter/nf_conntrack_standalone.c | 2 +-
> net/netfilter/nfnetlink_queue.c | 2 +-
> net/netlabel/netlabel_unlabeled.c | 21 +++---
> net/netlabel/netlabel_user.c | 14 ++--
> net/netlabel/netlabel_user.h | 6 +-
> net/xfrm/xfrm_policy.c | 8 ++-
> net/xfrm/xfrm_state.c | 18 +++--
> security/integrity/ima/ima_api.c | 6 +-
> security/integrity/integrity_audit.c | 5 +-
> security/security.c | 46 ++++++++-----
> security/smack/smackfs.c | 3 +-
> 23 files changed, 221 insertions(+), 90 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 2c3a2348a144..3520caa0260c 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -2722,7 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
> * case well anyway.
> */
> security_task_getsecid_obj(proc->tsk, &blob);
> - ret = security_secid_to_secctx(&blob, &lsmctx);
> + ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY);
> if (ret) {
> return_error = BR_FAILED_REPLY;
> return_error_param = ret;
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 97cd7471e572..85eb87f6f92d 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -291,6 +291,7 @@ extern int audit_alloc(struct task_struct *task);
> extern void __audit_free(struct task_struct *task);
> extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
> extern void audit_free_context(struct audit_context *context);
> +extern void audit_free_local(struct audit_context *context);
> extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
> unsigned long a2, unsigned long a3);
> extern void __audit_syscall_exit(int ret_success, long ret_value);
> @@ -386,6 +387,19 @@ static inline void audit_ptrace(struct task_struct *t)
> __audit_ptrace(t);
> }
>
> +static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp)
> +{
> + struct audit_context *context = audit_context();
> +
> + if (context)
> + return context;
> +
> + if (lsm_multiple_contexts())
> + return audit_alloc_local(gfp);
> +
> + return NULL;
> +}
We don't want to do this, at least not as it is written above. We
shouldn't have a function which abstracts away the creation of a local
audit_context. Usage of a local audit_context should be explicit in
the caller, and if the caller's execution context is ambiguous enough
that it can require both a task_struct audit_context and a local
audit_context then we need to handle that on a case-by-case basis.
Hiding it like this is guaranteed to cause problems later.
I probably did a poor job of explaining what a local context is during
the last patchset; I'll try to do a better job here but also let me
say this as clear as I can ... if the "current" task struct is valid
for a given code path, *never* use a local audit context. The local
audit context is a hack that is made necessary by the fact that we
have to audit things which happen outside the scope of an executing
task, e.g. the netfilter audit hooks, it should *never* be used when
there is a valid task_struct.
It's the audit_context which helps bind multiple audit records into a
single event, creating a new, "local" audit_context destroys that
binding as audit records created using that local audit_context have a
different timestamp from those records created using the current
task_struct's audit_context.
Hopefully that makes sense?
> /* Private API (for audit.c only) */
> extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
> extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
> @@ -560,6 +574,8 @@ extern int audit_signals;
> }
> static inline void audit_free_context(struct audit_context *context)
> { }
> +static inline void audit_free_local(struct audit_context *context)
> +{ }
> static inline int audit_alloc(struct task_struct *task)
> {
> return 0;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 3e9743118fb9..b3cf68cf2bd6 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -182,6 +182,8 @@ struct lsmblob {
> #define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */
> #define LSMBLOB_NEEDED -2 /* Slot requested on initialization */
> #define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */
> +#define LSMBLOB_DISPLAY -4 /* Use the "display" slot */
> +#define LSMBLOB_FIRST -5 /* Use the default "display" slot */
>
> /**
> * lsmblob_init - initialize an lsmblob structure
> @@ -248,6 +250,15 @@ static inline u32 lsmblob_value(const struct lsmblob *blob)
> return 0;
> }
>
> +static inline bool lsm_multiple_contexts(void)
> +{
> +#ifdef CONFIG_SECURITY
> + return lsm_slot_to_name(1) != NULL;
> +#else
> + return false;
> +#endif
> +}
> +
> /* These functions are in security/commoncap.c */
> extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
> int cap, unsigned int opts);
> @@ -578,7 +589,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> size_t size);
> int security_netlink_send(struct sock *sk, struct sk_buff *skb);
> int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
> + int display);
> int security_secctx_to_secid(const char *secdata, u32 seclen,
> struct lsmblob *blob);
> void security_release_secctx(struct lsmcontext *cp);
> @@ -1433,7 +1445,7 @@ static inline int security_ismaclabel(const char *name)
> }
>
> static inline int security_secid_to_secctx(struct lsmblob *blob,
> - struct lsmcontext *cp)
> + struct lsmcontext *cp, int display)
> {
> return -EOPNOTSUPP;
> }
> diff --git a/include/net/netlabel.h b/include/net/netlabel.h
> index 73fc25b4042b..216cb1ffc8f0 100644
> --- a/include/net/netlabel.h
> +++ b/include/net/netlabel.h
> @@ -97,7 +97,7 @@ struct calipso_doi;
>
> /* NetLabel audit information */
> struct netlbl_audit {
> - u32 secid;
> + struct lsmblob lsmdata;
> kuid_t loginuid;
> unsigned int sessionid;
> };
This chunk seems lost here, does it belong in another patch?
> diff --git a/include/net/scm.h b/include/net/scm.h
> index b77a52f93389..f4d567d4885e 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
> * and the infrastructure will know which it is.
> */
> lsmblob_init(&lb, scm->secid);
> - err = security_secid_to_secctx(&lb, &context);
> + err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
Misplaced code change?
> if (!err) {
> put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
> diff --git a/include/net/xfrm.h b/include/net/xfrm.h
> index cbff7c2a9724..a10fa01f7bf4 100644
> --- a/include/net/xfrm.h
> +++ b/include/net/xfrm.h
> @@ -660,13 +660,22 @@ struct xfrm_spi_skb_cb {
> #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
>
> #ifdef CONFIG_AUDITSYSCALL
> -static inline struct audit_buffer *xfrm_audit_start(const char *op)
> +static inline struct audit_buffer *xfrm_audit_start(const char *op,
> + struct audit_context **lac)
> {
> + struct audit_context *context;
> struct audit_buffer *audit_buf = NULL;
>
> if (audit_enabled == AUDIT_OFF)
> return NULL;
> - audit_buf = audit_log_start(audit_context(), GFP_ATOMIC,
> + context = audit_context();
> + if (lac != NULL) {
> + if (lsm_multiple_contexts() && context == NULL)
> + context = audit_alloc_local(GFP_ATOMIC);
> + *lac = context;
> + }
> +
> + audit_buf = audit_log_start(context, GFP_ATOMIC,
> AUDIT_MAC_IPSEC_EVENT);
> if (audit_buf == NULL)
> return NULL;
Related to the other comments around local audit_contexts, we don't
want to do this; use the existing audit_context, @lac in this case, so
that this audit record is bound to the other associated records into a
single audit event (all have the same timestamp).
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 841123390d41..cba63789a164 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -386,10 +386,12 @@ void audit_log_lost(const char *message)
> static int audit_log_config_change(char *function_name, u32 new, u32 old,
> int allow_changes)
> {
> + struct audit_context *context;
> struct audit_buffer *ab;
> int rc = 0;
>
> - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
> + context = audit_alloc_for_lsm(GFP_KERNEL);
> + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
We shouldn't need to do this for the reasons discussed up near the top
of this email (and elsewhere as well).
I'm going to refrain from commenting on the other uses of
audit_alloc_for_lsm() in this patch unless there is something unique
to the code path, so if you don't see me comment about a use of
audit_alloc_for_lsm() you can assume it should be removed and the
existing audit_context used instead.
> @@ -399,6 +401,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old,
> allow_changes = 0; /* Something weird, deny request */
> audit_log_format(ab, " res=%d", allow_changes);
> audit_log_end(ab);
> + audit_free_local(context);
See my comment directly above regarding usage of
audit_alloc_for_lsm(), it obviously applies here too.
> @@ -2128,6 +2136,36 @@ void audit_log_key(struct audit_buffer *ab, char *key)
> audit_log_format(ab, "(null)");
> }
>
> +static void audit_log_lsm(struct audit_context *context, struct lsmblob *blob)
See my note below about moving this into audit_log_task_context(), but
if we really need to keep this as a separate function, let's consider
changing the name to something which indicates that it logs the LSM
data as *subject* fields. How about audit_log_lsm_subj()?
> +{
> + struct audit_buffer *ab;
> + struct lsmcontext lsmdata;
> + bool sep = false;
> + int error;
> + int i;
> +
> + ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS);
> + if (!ab)
> + return; /* audit_panic or being filtered */
> +
> + for (i = 0; i < LSMBLOB_ENTRIES; i++) {
> + if (blob->secid[i] == 0)
> + continue;
> + error = security_secid_to_secctx(blob, &lsmdata, i);
> + if (error && error != -EINVAL) {
> + audit_panic("error in audit_log_lsm");
> + return;
> + }
> +
> + audit_log_format(ab, "%ssubj_%s=\"%s\"", sep ? " " : "",
> + lsm_slot_to_name(i), lsmdata.context);
> + sep = true;
Since @i starts at zero, you can get rid of @sep by replacing it with @i:
audit_log_format(ab, ..., (i ? " " : ""), ...);
> + security_release_secctx(&lsmdata);
> + }
> + audit_log_end(ab);
> +}
> @@ -2138,7 +2176,18 @@ int audit_log_task_context(struct audit_buffer *ab)
> if (!lsmblob_is_set(&blob))
> return 0;
>
> - error = security_secid_to_secctx(&blob, &context);
> + /*
> + * If there is more than one security module that has a
> + * subject "context" it's necessary to put the subject data
> + * into a separate record to maintain compatibility.
> + */
> + if (lsm_multiple_contexts()) {
> + audit_log_format(ab, " subj=?");
> + audit_log_lsm(ab->ctx, &blob);
> + return 0;
> + }
> +
> + error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
Instead of the lsm_multiple_contexts() case bailing on the rest of the
function with a return inside the if-block, let's made the code a bit
more robust by organizing it like this:
int audit_log_task_context(ab)
{
/* common stuff at the start */
if (lsm_multiple_contexts()) {
/* multi-LSM stuff */
} else {
/* single LSM stuff */
}
/* common stuff at the end */
}
... it also may make sense to just move the body of audit_log_lsm()
into audit_log_task_context() and do away with audit_log_lsm()
entirely; is it ever going to be called from anywhere else?
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 0e58a3ab56f5..01fdcbf468c0 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -993,12 +993,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags)
> context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
> if (!context) {
> audit_log_lost("out of memory in audit_alloc_local");
> - goto out;
> + return NULL;
> }
> context->serial = audit_serial();
> ktime_get_coarse_real_ts64(&context->ctime);
> context->local = true;
> -out:
> return context;
> }
This chunk should be moved to 21/25 when audit_alloc_local() is first defined.
> @@ -1019,6 +1018,13 @@ void audit_free_context(struct audit_context *context)
> }
> EXPORT_SYMBOL(audit_free_context);
>
> +void audit_free_local(struct audit_context *context)
> +{
> + if (context && context->local)
> + audit_free_context(context);
> +}
> +EXPORT_SYMBOL(audit_free_local);
If this is strictly necessary, and I don't think it is, it should also
be moved to patch 21/25 with the original definition of a local
audit_context. However, there really should be no reason why we have
to distinguish between a proper and local audtit_context when it comes
to free'ing the memory, just call audit_free_context() in both cases.
> @@ -1036,7 +1042,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> from_kuid(&init_user_ns, auid),
> from_kuid(&init_user_ns, uid), sessionid);
> if (lsmblob_is_set(blob)) {
> - if (security_secid_to_secctx(blob, &lsmctx)) {
> + if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
Misplaced code change?
Actually, there are a lot of these below, I'm not going to comment on
all of them as I think you get the idea ... and I very well may be
wrong so I'll save you all of my wrongness in that case :)
> diff --git a/security/security.c b/security/security.c
> index cb359e185d1a..5d7fd982f84a 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2309,7 +2309,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
> list) {
> rc = hp->hook.setprocattr(name, value, size);
> - if (rc < 0)
> + if (rc < 0 && rc != -EINVAL)
> return rc;
> }
This really looks misplaced ... ?
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-08-12 20:59 ` Paul Moore
@ 2021-08-12 22:38 ` Casey Schaufler
2021-08-13 15:31 ` Paul Moore
0 siblings, 1 reply; 15+ messages in thread
From: Casey Schaufler @ 2021-08-12 22:38 UTC (permalink / raw)
To: Paul Moore
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev, Casey Schaufler
On 8/12/2021 1:59 PM, Paul Moore wrote:
> On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>> Create a new audit record type to contain the subject information
>> when there are multiple security modules that require such data.
>> This record is linked with the same timestamp and serial number
>> using the audit_alloc_local() mechanism.
>> The record is produced only in cases where there is more than one
>> security module with a process "context".
>> In cases where this record is produced the subj= fields of
>> other records in the audit event will be set to "subj=?".
>>
>> An example of the MAC_TASK_CONTEXTS (1420) record is:
>>
>> type=UNKNOWN[1420]
>> msg=audit(1600880931.832:113)
>> subj_apparmor="=unconfined"
>> subj_smack="_"
>>
>> There will be a subj_$LSM= entry for each security module
>> LSM that supports the secid_to_secctx and secctx_to_secid
>> hooks. The BPF security module implements secid/secctx
>> translation hooks, so it has to be considered to provide a
>> secctx even though it may not actually do so.
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>> To: paul@paul-moore.com
>> To: linux-audit@redhat.com
>> To: rgb@redhat.com
>> Cc: netdev@vger.kernel.org
>> ---
>> drivers/android/binder.c | 2 +-
>> include/linux/audit.h | 16 +++++
>> include/linux/security.h | 16 ++++-
>> include/net/netlabel.h | 2 +-
>> include/net/scm.h | 2 +-
>> include/net/xfrm.h | 13 +++-
>> include/uapi/linux/audit.h | 1 +
>> kernel/audit.c | 90 +++++++++++++++++++------
>> kernel/auditfilter.c | 5 +-
>> kernel/auditsc.c | 27 ++++++--
>> net/ipv4/ip_sockglue.c | 2 +-
>> net/netfilter/nf_conntrack_netlink.c | 4 +-
>> net/netfilter/nf_conntrack_standalone.c | 2 +-
>> net/netfilter/nfnetlink_queue.c | 2 +-
>> net/netlabel/netlabel_unlabeled.c | 21 +++---
>> net/netlabel/netlabel_user.c | 14 ++--
>> net/netlabel/netlabel_user.h | 6 +-
>> net/xfrm/xfrm_policy.c | 8 ++-
>> net/xfrm/xfrm_state.c | 18 +++--
>> security/integrity/ima/ima_api.c | 6 +-
>> security/integrity/integrity_audit.c | 5 +-
>> security/security.c | 46 ++++++++-----
>> security/smack/smackfs.c | 3 +-
>> 23 files changed, 221 insertions(+), 90 deletions(-)
>>
>> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
>> index 2c3a2348a144..3520caa0260c 100644
>> --- a/drivers/android/binder.c
>> +++ b/drivers/android/binder.c
>> @@ -2722,7 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
>> * case well anyway.
>> */
>> security_task_getsecid_obj(proc->tsk, &blob);
>> - ret = security_secid_to_secctx(&blob, &lsmctx);
>> + ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY);
>> if (ret) {
>> return_error = BR_FAILED_REPLY;
>> return_error_param = ret;
>> diff --git a/include/linux/audit.h b/include/linux/audit.h
>> index 97cd7471e572..85eb87f6f92d 100644
>> --- a/include/linux/audit.h
>> +++ b/include/linux/audit.h
>> @@ -291,6 +291,7 @@ extern int audit_alloc(struct task_struct *task);
>> extern void __audit_free(struct task_struct *task);
>> extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
>> extern void audit_free_context(struct audit_context *context);
>> +extern void audit_free_local(struct audit_context *context);
>> extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
>> unsigned long a2, unsigned long a3);
>> extern void __audit_syscall_exit(int ret_success, long ret_value);
>> @@ -386,6 +387,19 @@ static inline void audit_ptrace(struct task_struct *t)
>> __audit_ptrace(t);
>> }
>>
>> +static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp)
>> +{
>> + struct audit_context *context = audit_context();
>> +
>> + if (context)
>> + return context;
>> +
>> + if (lsm_multiple_contexts())
>> + return audit_alloc_local(gfp);
>> +
>> + return NULL;
>> +}
> We don't want to do this, at least not as it is written above. We
> shouldn't have a function which abstracts away the creation of a local
> audit_context. Usage of a local audit_context should be explicit in
> the caller, and if the caller's execution context is ambiguous enough
> that it can require both a task_struct audit_context and a local
> audit_context then we need to handle that on a case-by-case basis.
> Hiding it like this is guaranteed to cause problems later.
OK. Please understand that *every case* where I've used audit_alloc_for_lsm()
is a case where I have *verified* that context may be NULL. I will make
the change.
> I probably did a poor job of explaining what a local context is during
> the last patchset; I'll try to do a better job here but also let me
> say this as clear as I can ... if the "current" task struct is valid
> for a given code path, *never* use a local audit context.
I probably did a poor job of demonstrating that I never use a local
context where there's a valid current context.
> The local
> audit context is a hack that is made necessary by the fact that we
> have to audit things which happen outside the scope of an executing
> task, e.g. the netfilter audit hooks, it should *never* be used when
> there is a valid task_struct.
In the existing audit code a "current context" is only needed for
syscall events, so that's the only case where it's allocated. Would
you suggest that I track down the non-syscall events that include
subj= fields and add allocate a "current context" for them? I looked
into doing that, and it wouldn't be simple.
> It's the audit_context which helps bind multiple audit records into a
> single event, creating a new, "local" audit_context destroys that
> binding
... if there's a current context. There often isn't. That's why I'm
using a local context. There is not a "current" context available.
> as audit records created using that local audit_context have a
> different timestamp from those records created using the current
> task_struct's audit_context.
(Weeps) I only introduce a local context where there is no current
context available, so this is never a problem.
> Hopefully that makes sense?
Yes, it makes sense. Methinks you may believe that the current context
is available more regularly than it actually is.
I instrumented the audit event functions with:
WARN_ONCE(audit_context, "%s has context\n", __func__);
WARN_ONCE(!audit_context, "%s lacks context\n", __func__);
I only used local contexts where the 2nd WARN_ONCE was hit.
>> /* Private API (for audit.c only) */
>> extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
>> extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
>> @@ -560,6 +574,8 @@ extern int audit_signals;
>> }
>> static inline void audit_free_context(struct audit_context *context)
>> { }
>> +static inline void audit_free_local(struct audit_context *context)
>> +{ }
>> static inline int audit_alloc(struct task_struct *task)
>> {
>> return 0;
>> diff --git a/include/linux/security.h b/include/linux/security.h
>> index 3e9743118fb9..b3cf68cf2bd6 100644
>> --- a/include/linux/security.h
>> +++ b/include/linux/security.h
>> @@ -182,6 +182,8 @@ struct lsmblob {
>> #define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */
>> #define LSMBLOB_NEEDED -2 /* Slot requested on initialization */
>> #define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */
>> +#define LSMBLOB_DISPLAY -4 /* Use the "display" slot */
>> +#define LSMBLOB_FIRST -5 /* Use the default "display" slot */
>>
>> /**
>> * lsmblob_init - initialize an lsmblob structure
>> @@ -248,6 +250,15 @@ static inline u32 lsmblob_value(const struct lsmblob *blob)
>> return 0;
>> }
>>
>> +static inline bool lsm_multiple_contexts(void)
>> +{
>> +#ifdef CONFIG_SECURITY
>> + return lsm_slot_to_name(1) != NULL;
>> +#else
>> + return false;
>> +#endif
>> +}
>> +
>> /* These functions are in security/commoncap.c */
>> extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
>> int cap, unsigned int opts);
>> @@ -578,7 +589,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>> size_t size);
>> int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>> int security_ismaclabel(const char *name);
>> -int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
>> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
>> + int display);
>> int security_secctx_to_secid(const char *secdata, u32 seclen,
>> struct lsmblob *blob);
>> void security_release_secctx(struct lsmcontext *cp);
>> @@ -1433,7 +1445,7 @@ static inline int security_ismaclabel(const char *name)
>> }
>>
>> static inline int security_secid_to_secctx(struct lsmblob *blob,
>> - struct lsmcontext *cp)
>> + struct lsmcontext *cp, int display)
>> {
>> return -EOPNOTSUPP;
>> }
>> diff --git a/include/net/netlabel.h b/include/net/netlabel.h
>> index 73fc25b4042b..216cb1ffc8f0 100644
>> --- a/include/net/netlabel.h
>> +++ b/include/net/netlabel.h
>> @@ -97,7 +97,7 @@ struct calipso_doi;
>>
>> /* NetLabel audit information */
>> struct netlbl_audit {
>> - u32 secid;
>> + struct lsmblob lsmdata;
>> kuid_t loginuid;
>> unsigned int sessionid;
>> };
> This chunk seems lost here, does it belong in another patch?
Probably. I am getting a touch of patch-rot showing up.
>> diff --git a/include/net/scm.h b/include/net/scm.h
>> index b77a52f93389..f4d567d4885e 100644
>> --- a/include/net/scm.h
>> +++ b/include/net/scm.h
>> @@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>> * and the infrastructure will know which it is.
>> */
>> lsmblob_init(&lb, scm->secid);
>> - err = security_secid_to_secctx(&lb, &context);
>> + err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
> Misplaced code change?
Same here.
>> if (!err) {
>> put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
>> diff --git a/include/net/xfrm.h b/include/net/xfrm.h
>> index cbff7c2a9724..a10fa01f7bf4 100644
>> --- a/include/net/xfrm.h
>> +++ b/include/net/xfrm.h
>> @@ -660,13 +660,22 @@ struct xfrm_spi_skb_cb {
>> #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
>>
>> #ifdef CONFIG_AUDITSYSCALL
>> -static inline struct audit_buffer *xfrm_audit_start(const char *op)
>> +static inline struct audit_buffer *xfrm_audit_start(const char *op,
>> + struct audit_context **lac)
>> {
>> + struct audit_context *context;
>> struct audit_buffer *audit_buf = NULL;
>>
>> if (audit_enabled == AUDIT_OFF)
>> return NULL;
>> - audit_buf = audit_log_start(audit_context(), GFP_ATOMIC,
>> + context = audit_context();
>> + if (lac != NULL) {
>> + if (lsm_multiple_contexts() && context == NULL)
>> + context = audit_alloc_local(GFP_ATOMIC);
>> + *lac = context;
>> + }
>> +
>> + audit_buf = audit_log_start(context, GFP_ATOMIC,
>> AUDIT_MAC_IPSEC_EVENT);
>> if (audit_buf == NULL)
>> return NULL;
> Related to the other comments around local audit_contexts, we don't
> want to do this; use the existing audit_context, @lac in this case, so
> that this audit record is bound to the other associated records into a
> single audit event (all have the same timestamp).
Hmm. This is clearly a problem. Looks like a change came in
that I didn't see.
>> diff --git a/kernel/audit.c b/kernel/audit.c
>> index 841123390d41..cba63789a164 100644
>> --- a/kernel/audit.c
>> +++ b/kernel/audit.c
>> @@ -386,10 +386,12 @@ void audit_log_lost(const char *message)
>> static int audit_log_config_change(char *function_name, u32 new, u32 old,
>> int allow_changes)
>> {
>> + struct audit_context *context;
>> struct audit_buffer *ab;
>> int rc = 0;
>>
>> - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
>> + context = audit_alloc_for_lsm(GFP_KERNEL);
>> + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
> We shouldn't need to do this for the reasons discussed up near the top
> of this email (and elsewhere as well).
Here and elsewhere, I only put audit_alloc_for_lsm() in because there
are cases where audit_context() returns NULL. Really.
>
> I'm going to refrain from commenting on the other uses of
> audit_alloc_for_lsm() in this patch unless there is something unique
> to the code path, so if you don't see me comment about a use of
> audit_alloc_for_lsm() you can assume it should be removed and the
> existing audit_context used instead.
>
>> @@ -399,6 +401,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old,
>> allow_changes = 0; /* Something weird, deny request */
>> audit_log_format(ab, " res=%d", allow_changes);
>> audit_log_end(ab);
>> + audit_free_local(context);
> See my comment directly above regarding usage of
> audit_alloc_for_lsm(), it obviously applies here too.
>
>> @@ -2128,6 +2136,36 @@ void audit_log_key(struct audit_buffer *ab, char *key)
>> audit_log_format(ab, "(null)");
>> }
>>
>> +static void audit_log_lsm(struct audit_context *context, struct lsmblob *blob)
> See my note below about moving this into audit_log_task_context(),
Either works for me. This seemed consistent with the rest of the audit
code, but I'm happy to change it if you like that better.
> but
> if we really need to keep this as a separate function, let's consider
> changing the name to something which indicates that it logs the LSM
> data as *subject* fields. How about audit_log_lsm_subj()?
>
>> +{
>> + struct audit_buffer *ab;
>> + struct lsmcontext lsmdata;
>> + bool sep = false;
>> + int error;
>> + int i;
>> +
>> + ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS);
>> + if (!ab)
>> + return; /* audit_panic or being filtered */
>> +
>> + for (i = 0; i < LSMBLOB_ENTRIES; i++) {
>> + if (blob->secid[i] == 0)
>> + continue;
>> + error = security_secid_to_secctx(blob, &lsmdata, i);
>> + if (error && error != -EINVAL) {
>> + audit_panic("error in audit_log_lsm");
>> + return;
>> + }
>> +
>> + audit_log_format(ab, "%ssubj_%s=\"%s\"", sep ? " " : "",
>> + lsm_slot_to_name(i), lsmdata.context);
>> + sep = true;
> Since @i starts at zero, you can get rid of @sep by replacing it with @i:
>
> audit_log_format(ab, ..., (i ? " " : ""), ...);
Clever.
>
>> + security_release_secctx(&lsmdata);
>> + }
>> + audit_log_end(ab);
>> +}
>> @@ -2138,7 +2176,18 @@ int audit_log_task_context(struct audit_buffer *ab)
>> if (!lsmblob_is_set(&blob))
>> return 0;
>>
>> - error = security_secid_to_secctx(&blob, &context);
>> + /*
>> + * If there is more than one security module that has a
>> + * subject "context" it's necessary to put the subject data
>> + * into a separate record to maintain compatibility.
>> + */
>> + if (lsm_multiple_contexts()) {
>> + audit_log_format(ab, " subj=?");
>> + audit_log_lsm(ab->ctx, &blob);
>> + return 0;
>> + }
>> +
>> + error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
> Instead of the lsm_multiple_contexts() case bailing on the rest of the
> function with a return inside the if-block, let's made the code a bit
> more robust by organizing it like this:
Sure, why not?
>
> int audit_log_task_context(ab)
> {
> /* common stuff at the start */
>
> if (lsm_multiple_contexts()) {
> /* multi-LSM stuff */
> } else {
> /* single LSM stuff */
> }
>
> /* common stuff at the end */
> }
>
> ... it also may make sense to just move the body of audit_log_lsm()
> into audit_log_task_context() and do away with audit_log_lsm()
> entirely; is it ever going to be called from anywhere else?
>
>> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
>> index 0e58a3ab56f5..01fdcbf468c0 100644
>> --- a/kernel/auditsc.c
>> +++ b/kernel/auditsc.c
>> @@ -993,12 +993,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags)
>> context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
>> if (!context) {
>> audit_log_lost("out of memory in audit_alloc_local");
>> - goto out;
>> + return NULL;
>> }
>> context->serial = audit_serial();
>> ktime_get_coarse_real_ts64(&context->ctime);
>> context->local = true;
>> -out:
>> return context;
>> }
> This chunk should be moved to 21/25 when audit_alloc_local() is first defined.
True. I was trying to minimize the change to the original audit_alloc_local()
patch on the assumption that it was coming in for other reasons, but that hasn't
happened.
>> @@ -1019,6 +1018,13 @@ void audit_free_context(struct audit_context *context)
>> }
>> EXPORT_SYMBOL(audit_free_context);
>>
>> +void audit_free_local(struct audit_context *context)
>> +{
>> + if (context && context->local)
>> + audit_free_context(context);
>> +}
>> +EXPORT_SYMBOL(audit_free_local);
> If this is strictly necessary, and I don't think it is, it should also
> be moved to patch 21/25 with the original definition of a local
> audit_context. However, there really should be no reason why we have
> to distinguish between a proper and local audtit_context when it comes
> to free'ing the memory, just call audit_free_context() in both cases.
>
>> @@ -1036,7 +1042,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>> from_kuid(&init_user_ns, auid),
>> from_kuid(&init_user_ns, uid), sessionid);
>> if (lsmblob_is_set(blob)) {
>> - if (security_secid_to_secctx(blob, &lsmctx)) {
>> + if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
> Misplaced code change?
>
> Actually, there are a lot of these below, I'm not going to comment on
> all of them as I think you get the idea ... and I very well may be
> wrong so I'll save you all of my wrongness in that case :)
>
>> diff --git a/security/security.c b/security/security.c
>> index cb359e185d1a..5d7fd982f84a 100644
>> --- a/security/security.c
>> +++ b/security/security.c
>> @@ -2309,7 +2309,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>> hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
>> list) {
>> rc = hp->hook.setprocattr(name, value, size);
>> - if (rc < 0)
>> + if (rc < 0 && rc != -EINVAL)
>> return rc;
>> }
> This really looks misplaced ... ?
Yeah, you're not the first person to notice these bits of patch-rot.
I have some clean-up to do.
Thank you for the review.
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-08-12 22:38 ` Casey Schaufler
@ 2021-08-13 15:31 ` Paul Moore
2021-08-13 18:48 ` Casey Schaufler
0 siblings, 1 reply; 15+ messages in thread
From: Paul Moore @ 2021-08-13 15:31 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev
On Thu, Aug 12, 2021 at 6:38 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> On 8/12/2021 1:59 PM, Paul Moore wrote:
> > On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >> Create a new audit record type to contain the subject information
> >> when there are multiple security modules that require such data.
...
> > The local
> > audit context is a hack that is made necessary by the fact that we
> > have to audit things which happen outside the scope of an executing
> > task, e.g. the netfilter audit hooks, it should *never* be used when
> > there is a valid task_struct.
>
> In the existing audit code a "current context" is only needed for
> syscall events, so that's the only case where it's allocated. Would
> you suggest that I track down the non-syscall events that include
> subj= fields and add allocate a "current context" for them? I looked
> into doing that, and it wouldn't be simple.
This is why the "local context" was created. Prior to these stacking
additions, and the audit container ID work, we never needed to group
multiple audit records outside of a syscall context into a single
audit event so passing a NULL context into audit_log_start() was
reasonable. The local context was designed as a way to generate a
context for use in a local function scope to group multiple records,
however, for reasons I'll get to below I'm now wondering if the local
context approach is really workable ...
> > Hopefully that makes sense?
>
> Yes, it makes sense. Methinks you may believe that the current context
> is available more regularly than it actually is.
>
> I instrumented the audit event functions with:
>
> WARN_ONCE(audit_context, "%s has context\n", __func__);
> WARN_ONCE(!audit_context, "%s lacks context\n", __func__);
>
> I only used local contexts where the 2nd WARN_ONCE was hit.
What does your audit config look like? Both the kernel command line
and the output of 'auditctl -l' would be helpful.
I'm beginning to suspect that you have the default
we-build-audit-into-the-kernel-because-product-management-said-we-have-to-but-we-don't-actually-enable-it-at-runtime
audit configuration that is de rigueur for many distros these days.
If that is the case, there are many cases where you would not see a
NULL current->audit_context simply because the config never allocated
one, see kernel/auditsc.c:audit_alloc(). If that is the case, I'm
honestly a little surprised we didn't realize that earlier, especially
given all the work/testing that Richard has done with the audit
container ID bits, but then again he surely had a proper audit config
during his testing so it wouldn't have appeared.
Good times.
Regardless, assuming that is the case we probably need to find an
alternative to the local context approach as it currently works. For
reasons we already talked about, we don't want to use a local
audit_context if there is the possibility for a proper
current->audit_context, but we need to do *something* so that we can
group these multiple events into a single record.
Since this is just occurring to me now I need a bit more time to think
on possible solutions - all good ideas are welcome - but the first
thing that pops into my head is that we need to augment
audit_log_end() to potentially generated additional, associated
records similar to what we do on syscall exit in audit_log_exit(). Of
course the audit_log_end() changes would be much more limited than
audit_log_exit(), just the LSM subject and audit container ID info,
and even then we might want to limit that to cases where the ab->ctx
value is NULL and let audit_log_exit() handle it otherwise. We may
need to store the event type in the audit_buffer during
audit_log_start() so that we can later use that in audit_log_end() to
determine what additional records are needed.
Regardless, let's figure out why all your current->audit_context
values are NULL first (report back on your audit config please), I may
be worrying about a hypothetical that isn't real.
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-08-13 15:31 ` Paul Moore
@ 2021-08-13 18:48 ` Casey Schaufler
2021-08-13 20:43 ` Paul Moore
0 siblings, 1 reply; 15+ messages in thread
From: Casey Schaufler @ 2021-08-13 18:48 UTC (permalink / raw)
To: Paul Moore
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev, Casey Schaufler
On 8/13/2021 8:31 AM, Paul Moore wrote:
> On Thu, Aug 12, 2021 at 6:38 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>> On 8/12/2021 1:59 PM, Paul Moore wrote:
>>> On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>>>> Create a new audit record type to contain the subject information
>>>> when there are multiple security modules that require such data.
> ...
>
>>> The local
>>> audit context is a hack that is made necessary by the fact that we
>>> have to audit things which happen outside the scope of an executing
>>> task, e.g. the netfilter audit hooks, it should *never* be used when
>>> there is a valid task_struct.
>> In the existing audit code a "current context" is only needed for
>> syscall events, so that's the only case where it's allocated. Would
>> you suggest that I track down the non-syscall events that include
>> subj= fields and add allocate a "current context" for them? I looked
>> into doing that, and it wouldn't be simple.
> This is why the "local context" was created. Prior to these stacking
> additions, and the audit container ID work, we never needed to group
> multiple audit records outside of a syscall context into a single
> audit event so passing a NULL context into audit_log_start() was
> reasonable. The local context was designed as a way to generate a
> context for use in a local function scope to group multiple records,
> however, for reasons I'll get to below I'm now wondering if the local
> context approach is really workable ...
I haven't found a place where it didn't work. What is the concern?
>>> Hopefully that makes sense?
>> Yes, it makes sense. Methinks you may believe that the current context
>> is available more regularly than it actually is.
>>
>> I instrumented the audit event functions with:
>>
>> WARN_ONCE(audit_context, "%s has context\n", __func__);
>> WARN_ONCE(!audit_context, "%s lacks context\n", __func__);
>>
>> I only used local contexts where the 2nd WARN_ONCE was hit.
> What does your audit config look like? Both the kernel command line
> and the output of 'auditctl -l' would be helpful.
On the fedora system:
BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.14.0-rc5stack+
root=/dev/mapper/fedora-root ro resume=/dev/mapper/fedora-swap
rd.lvm.lv=fedora/root rd.lvm.lv=fedora/swap lsm.debug
-a always,exit -F arch=b64 -S bpf -F key=testsuite-1628714321-EtlWIphW
On the Ubuntu system:
BOOT_IMAGE=/boot/vmlinuz-5.14.0-rc1stack+
root=UUID=39c25777-d413-4c2e-948c-dfa2bf259049 ro lsm.debug
No rules
> I'm beginning to suspect that you have the default
> we-build-audit-into-the-kernel-because-product-management-said-we-have-to-but-we-don't-actually-enable-it-at-runtime
> audit configuration that is de rigueur for many distros these days.
Yes, but I've also fiddled about with it so as to get better event coverage.
I've run the audit-testsuite, which has got to fiddle about with the audit
configuration.
> If that is the case, there are many cases where you would not see a
> NULL current->audit_context simply because the config never allocated
> one, see kernel/auditsc.c:audit_alloc().
I assume you mean that I *would* see a NULL current->audit_context
in the "event not enabled" case.
> If that is the case, I'm
> honestly a little surprised we didn't realize that earlier, especially
> given all the work/testing that Richard has done with the audit
> container ID bits, but then again he surely had a proper audit config
> during his testing so it wouldn't have appeared.
>
> Good times.
Indeed.
> Regardless, assuming that is the case we probably need to find an
> alternative to the local context approach as it currently works. For
> reasons we already talked about, we don't want to use a local
> audit_context if there is the possibility for a proper
> current->audit_context, but we need to do *something* so that we can
> group these multiple events into a single record.
I tried a couple things, but neither was satisfactory.
> Since this is just occurring to me now I need a bit more time to think
> on possible solutions - all good ideas are welcome - but the first
> thing that pops into my head is that we need to augment
> audit_log_end() to potentially generated additional, associated
> records similar to what we do on syscall exit in audit_log_exit().
I looked into that. You need a place to save the timestamp
that doesn't disappear. That's the role the audit_context plays
now.
> Of
> course the audit_log_end() changes would be much more limited than
> audit_log_exit(), just the LSM subject and audit container ID info,
> and even then we might want to limit that to cases where the ab->ctx
> value is NULL and let audit_log_exit() handle it otherwise. We may
> need to store the event type in the audit_buffer during
> audit_log_start() so that we can later use that in audit_log_end() to
> determine what additional records are needed.
>
> Regardless, let's figure out why all your current->audit_context
> values are NULL
That's what's maddening, and why I implemented audit_alloc_for_lsm().
They aren't all NULL. Sometimes current->audit_context is NULL,
sometimes it isn't, for the same event. I thought it might be a
question of the netlink interface being treated specially, but
that doesn't explain all the cases.
> first (report back on your audit config please), I may
> be worrying about a hypothetical that isn't real.
>
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-08-13 18:48 ` Casey Schaufler
@ 2021-08-13 20:43 ` Paul Moore
2021-08-13 21:47 ` Casey Schaufler
0 siblings, 1 reply; 15+ messages in thread
From: Paul Moore @ 2021-08-13 20:43 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev
On Fri, Aug 13, 2021 at 2:48 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> On 8/13/2021 8:31 AM, Paul Moore wrote:
> > On Thu, Aug 12, 2021 at 6:38 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >> On 8/12/2021 1:59 PM, Paul Moore wrote:
> >>> On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >>>> Create a new audit record type to contain the subject information
> >>>> when there are multiple security modules that require such data.
> > ...
> >
> >>> The local
> >>> audit context is a hack that is made necessary by the fact that we
> >>> have to audit things which happen outside the scope of an executing
> >>> task, e.g. the netfilter audit hooks, it should *never* be used when
> >>> there is a valid task_struct.
> >> In the existing audit code a "current context" is only needed for
> >> syscall events, so that's the only case where it's allocated. Would
> >> you suggest that I track down the non-syscall events that include
> >> subj= fields and add allocate a "current context" for them? I looked
> >> into doing that, and it wouldn't be simple.
> >
> > This is why the "local context" was created. Prior to these stacking
> > additions, and the audit container ID work, we never needed to group
> > multiple audit records outside of a syscall context into a single
> > audit event so passing a NULL context into audit_log_start() was
> > reasonable. The local context was designed as a way to generate a
> > context for use in a local function scope to group multiple records,
> > however, for reasons I'll get to below I'm now wondering if the local
> > context approach is really workable ...
>
> I haven't found a place where it didn't work. What is the concern?
The concern is that use of a local context can destroy any hopes of
linking with other related records, e.g. SYSCALL and PATH records, to
form a single cohesive event. If the current task_struct is valid for
a given function invocation then we *really* should be using current's
audit_context.
However, based on our discussion here it would seem that we may have
some issues where current->audit_context is not being managed
correctly. I'm not surprised, but I will admit to being disappointed.
> > What does your audit config look like? Both the kernel command line
> > and the output of 'auditctl -l' would be helpful.
>
> On the fedora system:
>
> BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.14.0-rc5stack+
> root=/dev/mapper/fedora-root ro resume=/dev/mapper/fedora-swap
> rd.lvm.lv=fedora/root rd.lvm.lv=fedora/swap lsm.debug
>
> -a always,exit -F arch=b64 -S bpf -F key=testsuite-1628714321-EtlWIphW
>
> On the Ubuntu system:
>
> BOOT_IMAGE=/boot/vmlinuz-5.14.0-rc1stack+
> root=UUID=39c25777-d413-4c2e-948c-dfa2bf259049 ro lsm.debug
>
> No rules
The Fedora system looks to have some audit-testsuite leftovers, but
that shouldn't have an impact on what we are discussing; in both cases
I would expect current->audit_context to be allocated and non-NULL.
> > I'm beginning to suspect that you have the default
> > we-build-audit-into-the-kernel-because-product-management-said-we-have-to-but-we-don't-actually-enable-it-at-runtime
> > audit configuration that is de rigueur for many distros these days.
>
> Yes, but I've also fiddled about with it so as to get better event coverage.
> I've run the audit-testsuite, which has got to fiddle about with the audit
> configuration.
Yes, it looks like my hunch was wrong.
> > If that is the case, there are many cases where you would not see a
> > NULL current->audit_context simply because the config never allocated
> > one, see kernel/auditsc.c:audit_alloc().
>
> I assume you mean that I *would* see a NULL current->audit_context
> in the "event not enabled" case.
Yep, typo.
> > Regardless, assuming that is the case we probably need to find an
> > alternative to the local context approach as it currently works. For
> > reasons we already talked about, we don't want to use a local
> > audit_context if there is the possibility for a proper
> > current->audit_context, but we need to do *something* so that we can
> > group these multiple events into a single record.
>
> I tried a couple things, but neither was satisfactory.
>
> > Since this is just occurring to me now I need a bit more time to think
> > on possible solutions - all good ideas are welcome - but the first
> > thing that pops into my head is that we need to augment
> > audit_log_end() to potentially generated additional, associated
> > records similar to what we do on syscall exit in audit_log_exit().
>
> I looked into that. You need a place to save the timestamp
> that doesn't disappear. That's the role the audit_context plays
> now.
Yes, I've spent a few hours staring at the poorly planned struct that
is audit_context ;)
Regardless, the obvious place for such a thing is audit_buffer; we can
stash whatever we need in there.
> > Of
> > course the audit_log_end() changes would be much more limited than
> > audit_log_exit(), just the LSM subject and audit container ID info,
> > and even then we might want to limit that to cases where the ab->ctx
> > value is NULL and let audit_log_exit() handle it otherwise. We may
> > need to store the event type in the audit_buffer during
> > audit_log_start() so that we can later use that in audit_log_end() to
> > determine what additional records are needed.
> >
> > Regardless, let's figure out why all your current->audit_context
> > values are NULL
>
> That's what's maddening, and why I implemented audit_alloc_for_lsm().
> They aren't all NULL. Sometimes current->audit_context is NULL,
> sometimes it isn't, for the same event. I thought it might be a
> question of the netlink interface being treated specially, but
> that doesn't explain all the cases.
Your netlink changes are exactly what made me think, "this is
obviously wrong", but now I'm wondering if a previously held
assumption of "current is valid and points to the calling process" in
the case of the kernel servicing netlink messages sent from userspace.
Or rather, perhaps that assumption is still true but something is
causing current->audit_context to be NULL in that case.
Friday the 13th indeed.
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-08-13 20:43 ` Paul Moore
@ 2021-08-13 21:47 ` Casey Schaufler
2021-08-16 18:57 ` Paul Moore
0 siblings, 1 reply; 15+ messages in thread
From: Casey Schaufler @ 2021-08-13 21:47 UTC (permalink / raw)
To: Paul Moore
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev, Casey Schaufler
On 8/13/2021 1:43 PM, Paul Moore wrote:
> On Fri, Aug 13, 2021 at 2:48 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>> On 8/13/2021 8:31 AM, Paul Moore wrote:
>>> On Thu, Aug 12, 2021 at 6:38 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>>>> On 8/12/2021 1:59 PM, Paul Moore wrote:
>>>>> On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>>>>>> Create a new audit record type to contain the subject information
>>>>>> when there are multiple security modules that require such data.
>>> ...
>>>
>>>>> The local
>>>>> audit context is a hack that is made necessary by the fact that we
>>>>> have to audit things which happen outside the scope of an executing
>>>>> task, e.g. the netfilter audit hooks, it should *never* be used when
>>>>> there is a valid task_struct.
>>>> In the existing audit code a "current context" is only needed for
>>>> syscall events, so that's the only case where it's allocated. Would
>>>> you suggest that I track down the non-syscall events that include
>>>> subj= fields and add allocate a "current context" for them? I looked
>>>> into doing that, and it wouldn't be simple.
>>> This is why the "local context" was created. Prior to these stacking
>>> additions, and the audit container ID work, we never needed to group
>>> multiple audit records outside of a syscall context into a single
>>> audit event so passing a NULL context into audit_log_start() was
>>> reasonable. The local context was designed as a way to generate a
>>> context for use in a local function scope to group multiple records,
>>> however, for reasons I'll get to below I'm now wondering if the local
>>> context approach is really workable ...
>> I haven't found a place where it didn't work. What is the concern?
> The concern is that use of a local context can destroy any hopes of
> linking with other related records, e.g. SYSCALL and PATH records, to
> form a single cohesive event. If the current task_struct is valid for
> a given function invocation then we *really* should be using current's
> audit_context.
>
> However, based on our discussion here it would seem that we may have
> some issues where current->audit_context is not being managed
> correctly. I'm not surprised, but I will admit to being disappointed.
I'd believe that with syscall audit being a special case for other reasons
the multiple record situation got taken care of on a case-by-case basis
and no one really paid much attention to generality. It's understandable.
>>> What does your audit config look like? Both the kernel command line
>>> and the output of 'auditctl -l' would be helpful.
>> On the fedora system:
>>
>> BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.14.0-rc5stack+
>> root=/dev/mapper/fedora-root ro resume=/dev/mapper/fedora-swap
>> rd.lvm.lv=fedora/root rd.lvm.lv=fedora/swap lsm.debug
>>
>> -a always,exit -F arch=b64 -S bpf -F key=testsuite-1628714321-EtlWIphW
>>
>> On the Ubuntu system:
>>
>> BOOT_IMAGE=/boot/vmlinuz-5.14.0-rc1stack+
>> root=UUID=39c25777-d413-4c2e-948c-dfa2bf259049 ro lsm.debug
>>
>> No rules
> The Fedora system looks to have some audit-testsuite leftovers, but
> that shouldn't have an impact on what we are discussing; in both cases
> I would expect current->audit_context to be allocated and non-NULL.
As would I.
>>> I'm beginning to suspect that you have the default
>>> we-build-audit-into-the-kernel-because-product-management-said-we-have-to-but-we-don't-actually-enable-it-at-runtime
>>> audit configuration that is de rigueur for many distros these days.
>> Yes, but I've also fiddled about with it so as to get better event coverage.
>> I've run the audit-testsuite, which has got to fiddle about with the audit
>> configuration.
> Yes, it looks like my hunch was wrong.
>
>>> If that is the case, there are many cases where you would not see a
>>> NULL current->audit_context simply because the config never allocated
>>> one, see kernel/auditsc.c:audit_alloc().
>> I assume you mean that I *would* see a NULL current->audit_context
>> in the "event not enabled" case.
> Yep, typo.
>
>>> Regardless, assuming that is the case we probably need to find an
>>> alternative to the local context approach as it currently works. For
>>> reasons we already talked about, we don't want to use a local
>>> audit_context if there is the possibility for a proper
>>> current->audit_context, but we need to do *something* so that we can
>>> group these multiple events into a single record.
>> I tried a couple things, but neither was satisfactory.
>>
>>> Since this is just occurring to me now I need a bit more time to think
>>> on possible solutions - all good ideas are welcome - but the first
>>> thing that pops into my head is that we need to augment
>>> audit_log_end() to potentially generated additional, associated
>>> records similar to what we do on syscall exit in audit_log_exit().
>> I looked into that. You need a place to save the timestamp
>> that doesn't disappear. That's the role the audit_context plays
>> now.
> Yes, I've spent a few hours staring at the poorly planned struct that
> is audit_context ;)
>
> Regardless, the obvious place for such a thing is audit_buffer; we can
> stash whatever we need in there.
I had considered doing that, but was afraid that moving the timestamp
out of the audit_context might have dire consequences.
>>> Of
>>> course the audit_log_end() changes would be much more limited than
>>> audit_log_exit(), just the LSM subject and audit container ID info,
>>> and even then we might want to limit that to cases where the ab->ctx
>>> value is NULL and let audit_log_exit() handle it otherwise. We may
>>> need to store the event type in the audit_buffer during
>>> audit_log_start() so that we can later use that in audit_log_end() to
>>> determine what additional records are needed.
>>>
>>> Regardless, let's figure out why all your current->audit_context
>>> values are NULL
>> That's what's maddening, and why I implemented audit_alloc_for_lsm().
>> They aren't all NULL. Sometimes current->audit_context is NULL,
>> sometimes it isn't, for the same event. I thought it might be a
>> question of the netlink interface being treated specially, but
>> that doesn't explain all the cases.
> Your netlink changes are exactly what made me think, "this is
> obviously wrong", but now I'm wondering if a previously held
> assumption of "current is valid and points to the calling process" in
> the case of the kernel servicing netlink messages sent from userspace.
If that's the case the subject data in the audit record is going
to be bogus. From what I've seen that data appears to be correct.
> Or rather, perhaps that assumption is still true but something is
> causing current->audit_context to be NULL in that case.
I can imagine someone deciding not to set up audit_context in
situations like netlink because they knew that nothing following
that would be a syscall event. I've been looking into the audit
userspace and there are assumptions like that all over the place.
> Friday the 13th indeed.
I've been banging my head against this for a couple months.
My biggest fear is that I may have learned enough about the
audit system to make useful contributions.
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
2021-08-13 21:47 ` Casey Schaufler
@ 2021-08-16 18:57 ` Paul Moore
0 siblings, 0 replies; 15+ messages in thread
From: Paul Moore @ 2021-08-16 18:57 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, James Morris, linux-security-module, selinux,
linux-audit, keescook, john.johansen, penguin-kernel,
Stephen Smalley, linux-kernel, netdev
On Fri, Aug 13, 2021 at 5:47 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> On 8/13/2021 1:43 PM, Paul Moore wrote:
> > On Fri, Aug 13, 2021 at 2:48 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >> On 8/13/2021 8:31 AM, Paul Moore wrote:
> >>> On Thu, Aug 12, 2021 at 6:38 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >>>> On 8/12/2021 1:59 PM, Paul Moore wrote:
> >>>>> On Wed, Jul 21, 2021 at 9:12 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >>>>>> Create a new audit record type to contain the subject information
> >>>>>> when there are multiple security modules that require such data.
> >>> ...
> >>>
> >>>>> The local
> >>>>> audit context is a hack that is made necessary by the fact that we
> >>>>> have to audit things which happen outside the scope of an executing
> >>>>> task, e.g. the netfilter audit hooks, it should *never* be used when
> >>>>> there is a valid task_struct.
> >>>> In the existing audit code a "current context" is only needed for
> >>>> syscall events, so that's the only case where it's allocated. Would
> >>>> you suggest that I track down the non-syscall events that include
> >>>> subj= fields and add allocate a "current context" for them? I looked
> >>>> into doing that, and it wouldn't be simple.
> >>> This is why the "local context" was created. Prior to these stacking
> >>> additions, and the audit container ID work, we never needed to group
> >>> multiple audit records outside of a syscall context into a single
> >>> audit event so passing a NULL context into audit_log_start() was
> >>> reasonable. The local context was designed as a way to generate a
> >>> context for use in a local function scope to group multiple records,
> >>> however, for reasons I'll get to below I'm now wondering if the local
> >>> context approach is really workable ...
> >> I haven't found a place where it didn't work. What is the concern?
> > The concern is that use of a local context can destroy any hopes of
> > linking with other related records, e.g. SYSCALL and PATH records, to
> > form a single cohesive event. If the current task_struct is valid for
> > a given function invocation then we *really* should be using current's
> > audit_context.
> >
> > However, based on our discussion here it would seem that we may have
> > some issues where current->audit_context is not being managed
> > correctly. I'm not surprised, but I will admit to being disappointed.
>
> I'd believe that with syscall audit being a special case for other reasons
> the multiple record situation got taken care of on a case-by-case basis
> and no one really paid much attention to generality. It's understandable.
>
> >>> What does your audit config look like? Both the kernel command line
> >>> and the output of 'auditctl -l' would be helpful.
> >> On the fedora system:
> >>
> >> BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.14.0-rc5stack+
> >> root=/dev/mapper/fedora-root ro resume=/dev/mapper/fedora-swap
> >> rd.lvm.lv=fedora/root rd.lvm.lv=fedora/swap lsm.debug
> >>
> >> -a always,exit -F arch=b64 -S bpf -F key=testsuite-1628714321-EtlWIphW
> >>
> >> On the Ubuntu system:
> >>
> >> BOOT_IMAGE=/boot/vmlinuz-5.14.0-rc1stack+
> >> root=UUID=39c25777-d413-4c2e-948c-dfa2bf259049 ro lsm.debug
> >>
> >> No rules
> > The Fedora system looks to have some audit-testsuite leftovers, but
> > that shouldn't have an impact on what we are discussing; in both cases
> > I would expect current->audit_context to be allocated and non-NULL.
>
> As would I.
>
>
> >>> I'm beginning to suspect that you have the default
> >>> we-build-audit-into-the-kernel-because-product-management-said-we-have-to-but-we-don't-actually-enable-it-at-runtime
> >>> audit configuration that is de rigueur for many distros these days.
> >> Yes, but I've also fiddled about with it so as to get better event coverage.
> >> I've run the audit-testsuite, which has got to fiddle about with the audit
> >> configuration.
> > Yes, it looks like my hunch was wrong.
> >
> >>> If that is the case, there are many cases where you would not see a
> >>> NULL current->audit_context simply because the config never allocated
> >>> one, see kernel/auditsc.c:audit_alloc().
> >> I assume you mean that I *would* see a NULL current->audit_context
> >> in the "event not enabled" case.
> > Yep, typo.
> >
> >>> Regardless, assuming that is the case we probably need to find an
> >>> alternative to the local context approach as it currently works. For
> >>> reasons we already talked about, we don't want to use a local
> >>> audit_context if there is the possibility for a proper
> >>> current->audit_context, but we need to do *something* so that we can
> >>> group these multiple events into a single record.
> >> I tried a couple things, but neither was satisfactory.
> >>
> >>> Since this is just occurring to me now I need a bit more time to think
> >>> on possible solutions - all good ideas are welcome - but the first
> >>> thing that pops into my head is that we need to augment
> >>> audit_log_end() to potentially generated additional, associated
> >>> records similar to what we do on syscall exit in audit_log_exit().
> >> I looked into that. You need a place to save the timestamp
> >> that doesn't disappear. That's the role the audit_context plays
> >> now.
> > Yes, I've spent a few hours staring at the poorly planned struct that
> > is audit_context ;)
> >
> > Regardless, the obvious place for such a thing is audit_buffer; we can
> > stash whatever we need in there.
>
> I had considered doing that, but was afraid that moving the timestamp
> out of the audit_context might have dire consequences.
Don't move, copy. If there is a valid context one would stash the
timestamp there, if not, we stash it in the audit_buffer. However,
before we start messing with that too much I would like to better
understand why we aren't seeing a valid audit_context in the netlink
case at the very least.
> >>> Of
> >>> course the audit_log_end() changes would be much more limited than
> >>> audit_log_exit(), just the LSM subject and audit container ID info,
> >>> and even then we might want to limit that to cases where the ab->ctx
> >>> value is NULL and let audit_log_exit() handle it otherwise. We may
> >>> need to store the event type in the audit_buffer during
> >>> audit_log_start() so that we can later use that in audit_log_end() to
> >>> determine what additional records are needed.
> >>>
> >>> Regardless, let's figure out why all your current->audit_context
> >>> values are NULL
> >> That's what's maddening, and why I implemented audit_alloc_for_lsm().
> >> They aren't all NULL. Sometimes current->audit_context is NULL,
> >> sometimes it isn't, for the same event. I thought it might be a
> >> question of the netlink interface being treated specially, but
> >> that doesn't explain all the cases.
> >
> > Your netlink changes are exactly what made me think, "this is
> > obviously wrong", but now I'm wondering if a previously held
> > assumption of "current is valid and points to the calling process" in
> > the case of the kernel servicing netlink messages sent from userspace.
>
> If that's the case the subject data in the audit record is going
> to be bogus. From what I've seen that data appears to be correct.
Yeah, the thought occurred to me, but we are clearly already in the
maybe-the-assumptions-are-wrong stage so I'm not going to rely on that
being 100%. We definitely need to track this down before we start
making to many more guesses about what is working and what is not.
> > Or rather, perhaps that assumption is still true but something is
> > causing current->audit_context to be NULL in that case.
>
> I can imagine someone deciding not to set up audit_context in
> situations like netlink because they knew that nothing following
> that would be a syscall event.
*If* the user/kernel transition happens as part of the netlink socket
send/write/etc. syscall then it *should* have all of the audit syscall
setup already done ... however, see my earlier comments about
assumptions :/
> I've been looking into the audit
> userspace and there are assumptions like that all over the place.
I've made my feelings about audit's design known quite a bit already
so I'm not going to drag all of that back up, all I'll say is that I
believe the audit design was tragically and inherently flawed in many
ways. We've been working to resolve some of those issues in the
kernel for a little while now, but the audit userspace remains rooted
in some of those original design decisions. Of course, these are just
my opinions, others clearly feel differently.
Regardless, and somewhat independent of our discussion here, now that
I am back to being able to dedicate a good chunk of my time to
upstream efforts, one of my priorities is to start repairing audit ...
however, I need to get past the io_uring mess first.
> > Friday the 13th indeed.
>
> I've been banging my head against this for a couple months.
> My biggest fear is that I may have learned enough about the
> audit system to make useful contributions.
As the usual refrain goes, "patches are always welcome" ... and I say
that with equal parts honesty and warning :)
Even if you aren't comfortable putting together a patch, simply
root-causing the missing audit_context setup in the netlink case would
be helpful.
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2021-08-16 18:57 UTC | newest]
Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-22 0:47 ` [PATCH v28 07/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 08/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 10/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 15/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 16/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2021-07-22 0:47 ` [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes Casey Schaufler
2021-08-12 20:59 ` Paul Moore
2021-08-12 22:38 ` Casey Schaufler
2021-08-13 15:31 ` Paul Moore
2021-08-13 18:48 ` Casey Schaufler
2021-08-13 20:43 ` Paul Moore
2021-08-13 21:47 ` Casey Schaufler
2021-08-16 18:57 ` Paul Moore
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