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From: Casey Schaufler <casey@schaufler-ca.com>
To: casey@schaufler-ca.com,
	paul@paul-moore.com,
	linux-security-module@vger.kernel.org
Cc: jmorris@namei.org,
	serge@hallyn.com,
	keescook@chromium.org,
	john.johansen@canonical.com,
	penguin-kernel@i-love.sakura.ne.jp,
	stephen.smalley.work@gmail.com,
	linux-kernel@vger.kernel.org,
	mic@digikod.net,
	linux-integrity@vger.kernel.org,
	audit@vger.kernel.org
Subject: [PATCH v39 11/42] LSM: Use lsmblob in security_inode_getsecid
Date: Fri, 15 Dec 2023 14:16:05 -0800
Message-ID: <20231215221636.105680-12-casey@schaufler-ca.com>
In-Reply-To: <20231215221636.105680-1-casey@schaufler-ca.com>
References: <20231215221636.105680-1-casey@schaufler-ca.com>
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Change the security_inode_getsecid() interface to fill in a
lsmblob structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit. Change the name to security_inode_getlsmblob().

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: audit@vger.kernel.org
---
 include/linux/lsm_hook_defs.h       |  3 ++-
 include/linux/security.h            |  7 ++++---
 kernel/auditsc.c                    |  6 +++++-
 security/integrity/ima/ima_policy.c |  3 +--
 security/security.c                 | 11 +++++------
 security/selinux/hooks.c            | 15 +++++++++------
 security/smack/smack_lsm.c          | 12 +++++++-----
 7 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 2db7320a1e05..3c51ee8e3d6c 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -161,7 +161,8 @@ LSM_HOOK(int, -EOPNOTSUPP, inode_setsecurity, struct inode *inode,
 	 const char *name, const void *value, size_t size, int flags)
 LSM_HOOK(int, 0, inode_listsecurity, struct inode *inode, char *buffer,
 	 size_t buffer_size)
-LSM_HOOK(void, LSM_RET_VOID, inode_getsecid, struct inode *inode, u32 *secid)
+LSM_HOOK(void, LSM_RET_VOID, inode_getlsmblob, struct inode *inode,
+	 struct lsmblob *blob)
 LSM_HOOK(int, 0, inode_copy_up, struct dentry *src, struct cred **new)
 LSM_HOOK(int, -EOPNOTSUPP, inode_copy_up_xattr, const char *name)
 LSM_HOOK(int, 0, kernfs_init_security, struct kernfs_node *kn_dir,
diff --git a/include/linux/security.h b/include/linux/security.h
index 6306e8ab0cf6..e8b7f858de04 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -431,7 +431,7 @@ int security_inode_getsecurity(struct mnt_idmap *idmap,
 			       void **buffer, bool alloc);
 int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
 int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
-void security_inode_getsecid(struct inode *inode, u32 *secid);
+void security_inode_getlsmblob(struct inode *inode, struct lsmblob *blob);
 int security_inode_copy_up(struct dentry *src, struct cred **new);
 int security_inode_copy_up_xattr(const char *name);
 int security_kernfs_init_security(struct kernfs_node *kn_dir,
@@ -1020,9 +1020,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
 	return 0;
 }
 
-static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
+static inline void security_inode_getlsmblob(struct inode *inode,
+					     struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob);
 }
 
 static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7afeae468745..b15e44e56409 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2276,13 +2276,17 @@ static void audit_copy_inode(struct audit_names *name,
 			     const struct dentry *dentry,
 			     struct inode *inode, unsigned int flags)
 {
+	struct lsmblob blob;
+
 	name->ino   = inode->i_ino;
 	name->dev   = inode->i_sb->s_dev;
 	name->mode  = inode->i_mode;
 	name->uid   = inode->i_uid;
 	name->gid   = inode->i_gid;
 	name->rdev  = inode->i_rdev;
-	security_inode_getsecid(inode, &name->osid);
+	security_inode_getlsmblob(inode, &blob);
+	/* stacking scaffolding */
+	name->osid = blob.scaffold.secid;
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 48287b75fe77..8edf7a0ef9f6 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -671,8 +671,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		case LSM_OBJ_USER:
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
-			/* stacking scaffolding */
-			security_inode_getsecid(inode, &blob.scaffold.secid);
+			security_inode_getlsmblob(inode, &blob);
 			rc = ima_filter_rule_match(&blob, lsm_rule->lsm[i].type,
 						   Audit_equal,
 						   lsm_rule->lsm[i].rule,
diff --git a/security/security.c b/security/security.c
index 58387e1f0c04..ed4e9b5fdf70 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2607,16 +2607,15 @@ int security_inode_listsecurity(struct inode *inode,
 EXPORT_SYMBOL(security_inode_listsecurity);
 
 /**
- * security_inode_getsecid() - Get an inode's secid
+ * security_inode_getlsmblob() - Get an inode's LSM data
  * @inode: inode
- * @secid: secid to return
+ * @blob: lsm specific information to return
  *
- * Get the secid associated with the node.  In case of failure, @secid will be
- * set to zero.
+ * Get the lsm specific information associated with the node.
  */
-void security_inode_getsecid(struct inode *inode, u32 *secid)
+void security_inode_getlsmblob(struct inode *inode, struct lsmblob *blob)
 {
-	call_void_hook(inode_getsecid, inode, secid);
+	call_void_hook(inode_getlsmblob, inode, blob);
 }
 
 /**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index d70000363b7a..4ab923698da9 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3496,15 +3496,18 @@ static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t
 	return len;
 }
 
-static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
+static void selinux_inode_getlsmblob(struct inode *inode, struct lsmblob *blob)
 {
 	struct inode_security_struct *isec = inode_security_novalidate(inode);
-	*secid = isec->sid;
+
+	blob->selinux.secid = isec->sid;
+	/* stacking scaffolding */
+	blob->scaffold.secid = isec->sid;
 }
 
 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
 {
-	u32 sid;
+	struct lsmblob blob;
 	struct task_security_struct *tsec;
 	struct cred *new_creds = *new;
 
@@ -3516,8 +3519,8 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
 
 	tsec = selinux_cred(new_creds);
 	/* Get label from overlay inode and set it in create_sid */
-	selinux_inode_getsecid(d_inode(src), &sid);
-	tsec->create_sid = sid;
+	selinux_inode_getlsmblob(d_inode(src), &blob);
+	tsec->create_sid = blob.selinux.secid;
 	*new = new_creds;
 	return 0;
 }
@@ -7125,7 +7128,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
 	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
 	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
 	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
-	LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
+	LSM_HOOK_INIT(inode_getlsmblob, selinux_inode_getlsmblob),
 	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
 	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
 	LSM_HOOK_INIT(path_notify, selinux_path_notify),
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 46cc79eb1200..e6d49e59a0c0 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1615,15 +1615,17 @@ static int smack_inode_listsecurity(struct inode *inode, char *buffer,
 }
 
 /**
- * smack_inode_getsecid - Extract inode's security id
+ * smack_inode_getlsmblob - Extract inode's security id
  * @inode: inode to extract the info from
- * @secid: where result will be saved
+ * @blob: where result will be saved
  */
-static void smack_inode_getsecid(struct inode *inode, u32 *secid)
+static void smack_inode_getlsmblob(struct inode *inode, struct lsmblob *blob)
 {
 	struct smack_known *skp = smk_of_inode(inode);
 
-	*secid = skp->smk_secid;
+	blob->smack.skp = skp;
+	/* stacking scaffolding */
+	blob->scaffold.secid = skp->smk_secid;
 }
 
 /*
@@ -5081,7 +5083,7 @@ static struct security_hook_list smack_hooks[] __ro_after_init = {
 	LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
 	LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
 	LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
-	LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
+	LSM_HOOK_INIT(inode_getlsmblob, smack_inode_getlsmblob),
 
 	LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
 	LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
-- 
2.41.0