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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 v11 06/25] LSM: Use lsmblob in security_secctx_to_secid
Date: Wed, 13 Nov 2019 09:57:02 -0800
Message-ID: <20191113175721.2317-7-casey@schaufler-ca.com> (raw)
In-Reply-To: <20191113175721.2317-1-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 d57f400a307e..b69877a13efa 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -494,7 +494,8 @@ 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);
@@ -1300,7 +1301,7 @@ 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 846ac4b23c16..7fef90f3f10b 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -756,14 +756,12 @@ 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 317e3a9e8c5b..7c49397c33fd 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -617,21 +617,20 @@ 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 2317721f3ecb..2d68416b4552 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -45,13 +45,14 @@ 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",
@@ -59,6 +60,8 @@ 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 d2e4ab8d1cb1..7a5a87f15736 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -881,7 +881,7 @@ 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
@@ -905,12 +905,13 @@ 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);
 }
 
@@ -932,7 +933,7 @@ 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
@@ -954,12 +955,13 @@ 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 55837706e3ef..32bb5383de9b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1970,10 +1970,22 @@ 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: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191113175721.2317-1-casey.ref@schaufler-ca.com>
2019-11-13 17:56 ` [PATCH v11 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-11-13 17:56   ` [PATCH v11 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
2019-11-13 17:56   ` [PATCH v11 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
2019-11-21  5:36     ` James Morris
2019-11-13 17:56   ` [PATCH v11 03/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2019-11-21  5:38     ` James Morris
2019-11-13 17:57   ` [PATCH v11 04/25] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 05/25] net: Prepare UDS for security module stacking Casey Schaufler
2019-11-13 17:57   ` Casey Schaufler [this message]
2019-11-13 17:57   ` [PATCH v11 07/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 08/25] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 09/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 10/25] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 11/25] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 12/25] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 13/25] LSM: Specify which LSM to display Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 14/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 15/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 16/25] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2019-11-13 17:57   ` [PATCH v11 17/25] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2019-11-21  5:50     ` James Morris
2019-11-13 17:57   ` [PATCH v11 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2019-11-13 18:19 [PATCH v11 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-11-13 18:19 ` [PATCH v11 06/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2019-11-21 18:42   ` John Johansen
  -- strict thread matches above, loose matches on Subject: below --
2019-11-13 16:50 [PATCH v11 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-11-13 16:50 ` [PATCH v11 06/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler

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