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From: Casey Schaufler <casey@schaufler-ca.com>
To: casey.schaufler@intel.com, jmorris@namei.org,
	linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc: casey@schaufler-ca.com, keescook@chromium.org,
	john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
	paul@paul-moore.com, sds@tycho.nsa.gov
Subject: [PATCH v8 08/28] LSM: Use lsmblob in security_secctx_to_secid
Date: Thu, 29 Aug 2019 16:29:15 -0700
Message-ID: <20190829232935.7099-9-casey@schaufler-ca.com> (raw)
In-Reply-To: <20190829232935.7099-1-casey@schaufler-ca.com>

Change security_secctx_to_secid() to fill in a lsmblob instead
of a u32 secid. Multiple LSMs may be able to interpret the
string, and this allows for setting whichever secid is
appropriate. In some cases there is scaffolding where other
interfaces have yet to be converted.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  5 +++--
 kernel/cred.c                     |  4 +---
 net/netfilter/nft_meta.c          | 13 ++++++-------
 net/netfilter/xt_SECMARK.c        |  5 ++++-
 net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
 security/security.c               | 18 +++++++++++++++---
 6 files changed, 37 insertions(+), 22 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index dcf20da87d1b..30337f1a9056 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -447,7 +447,8 @@ 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);
@@ -1230,7 +1231,7 @@ 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 71c14dda107e..d70a2c02ced4 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -725,14 +725,12 @@ 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 987d2d6ce624..054fb4b48d51 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -576,21 +576,20 @@ 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)
-		return -ENOENT;
-
-	err = security_secmark_relabel_packet(tmp_secid);
+	/* Using le[0] is scaffolding */
+	err = security_secmark_relabel_packet(blob.secid[0]);
 	if (err)
 		return err;
 
-	priv->secid = tmp_secid;
+	/* Using le[0] is scaffolding */
+	priv->secid = blob.secid[0];
 	return 0;
 }
 
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index f16202d26c20..8081fadc30e9 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -49,13 +49,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
 
 static int checkentry_lsm(struct xt_secmark_target_info *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",
@@ -63,6 +64,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
 		return err;
 	}
 
+	/* scaffolding during the transition */
+	info->secid = blob.secid[0];
 	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 c92894c3e40a..2976370e41aa 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -895,7 +895,7 @@ 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
@@ -919,12 +919,13 @@ 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;
 
+	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len, secid,
+				 dev_name, addr, mask, addr_len, blob.secid[0],
 				 &audit_info);
 }
 
@@ -946,7 +947,7 @@ 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
@@ -968,12 +969,13 @@ 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;
 
+	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len, secid,
+				 NULL, addr, mask, addr_len, blob.secid[0],
 				 &audit_info);
 }
 
diff --git a/security/security.c b/security/security.c
index fe76dfa0f2fd..e231fbfd68f2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1982,10 +1982,22 @@ 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);
 
-- 
2.20.1


  parent reply index

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-29 23:29 [PATCH v8 00/28] LSM: Module stacking for AppArmor Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 01/28] LSM: Infrastructure management of the superblock Casey Schaufler
2019-09-16 18:19   ` Stephen Smalley
2019-08-29 23:29 ` [PATCH v8 02/28] LSM: Infrastructure management of the sock security Casey Schaufler
2019-09-16 18:42   ` Stephen Smalley
2019-09-18  7:19     ` John Johansen
2019-08-29 23:29 ` [PATCH v8 03/28] LSM: Infrastructure management of the key blob Casey Schaufler
2019-09-16 18:47   ` Stephen Smalley
2019-08-29 23:29 ` [PATCH v8 04/28] LSM: Create and manage the lsmblob data structure Casey Schaufler
2019-09-16 19:15   ` Stephen Smalley
2019-09-23 15:56     ` Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 05/28] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 06/28] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 07/28] net: Prepare UDS for security module stacking Casey Schaufler
2019-08-29 23:29 ` Casey Schaufler [this message]
2019-08-29 23:29 ` [PATCH v8 09/28] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 10/28] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 11/28] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 12/28] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 13/28] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 14/28] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 15/28] LSM: Specify which LSM to display Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 16/28] LSM: Ensure the correct LSM context releaser Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 17/28] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 18/28] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 19/28] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 20/28] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 21/28] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 22/28] SELinux: Verify LSM display sanity in binder Casey Schaufler
2019-09-18 17:43   ` Stephen Smalley
2019-08-29 23:29 ` [PATCH v8 23/28] Audit: Add subj_LSM fields when necessary Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 24/28] Audit: Include object data for all security modules Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 25/28] LSM: Provide an user space interface for the default display Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 26/28] NET: Add SO_PEERCONTEXT for multiple LSMs Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 27/28] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2019-08-29 23:29 ` [PATCH v8 28/28] AppArmor: Remove the exclusive flag Casey Schaufler
2019-09-04 19:13 ` [PATCH v8 00/28] LSM: Module stacking for AppArmor Casey Schaufler
2019-09-06 13:46   ` Stephen Smalley

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