Automated merge of 'lsm/dev' into 'stable-7.4'

Manual merge fixup in ns_common_types.h:ns_common to work around a conflict
with the nsfs RCU grace period fix.

* lsm/dev:
  lsm: remove redundant NULL check in security_init()
  selftests/landlock: Check full ioctl commands in audit records
  lsm: Preserve full ioctl commands in audit records
  doc: fix LSM ordering description for /sys/kernel/security/lsm
  doc: describe CONFIG_LSM and lsm= as the selection mechanism
  selftests/bpf: verify mount idmaps reach inode hooks
  lsm: expose mount idmaps to inode hooks
  rust: lsm: replace `core::mem::zeroed` with `pin_init::zeroed`
  cred: prevent slab cache merging for cred_jar
  lsm: don't call security_backing_file_free() multiple times
  lsm: delete duplicate assignment in lsm_prepare()
  lsm: update the BUILD_BUG_ON() in audit_log_lsm_data()
  lsm: add LSM_AUDIT_DATA_NS for namespace audit records
  lsm: add LSM blob and hooks for namespaces
  ns: Free anonymous mount namespaces via ns_common_free()
  cred: clarify that task_struct::cred is only for the current task

7 files changed, 96 insertions, 44 deletions

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 6ef1750c93e2..49c26af37349 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -180,12 +180,18 @@ static inline bool cap_ambient_invariant_ok(const struct cred *cred)
 
 static inline const struct cred *override_creds(const struct cred *override_cred)
 {
-	return rcu_replace_pointer(current->cred, override_cred, 1);
+	const struct cred *old = current->cred;
+
+	current->cred = override_cred;
+	return old;
 }
 
 static inline const struct cred *revert_creds(const struct cred *revert_cred)
 {
-	return rcu_replace_pointer(current->cred, revert_cred, 1);
+	const struct cred *override_cred = current->cred;
+
+	current->cred = revert_cred;
+	return override_cred;
 }
 
 DEFINE_CLASS(override_creds,
@@ -293,11 +299,10 @@ DEFINE_FREE(put_cred, struct cred *, if (!IS_ERR_OR_NULL(_T)) put_cred(_T))
 /**
  * current_cred - Access the current task's subjective credentials
  *
- * Access the subjective credentials of the current task.  RCU-safe,
- * since nobody else can modify it.
+ * Access the subjective credentials of the current task.
+ * Nobody else can modify it.
  */
-#define current_cred() \
-	rcu_dereference_protected(current->cred, 1)
+#define current_cred() (current->cred)
 
 /**
  * current_real_cred - Access the current task's objective credentials
diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index 584db296e43b..5cf0b4795065 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -44,7 +44,7 @@ struct lsm_network_audit {
 
 struct lsm_ioctlop_audit {
 	struct path path;
-	u16 cmd;
+	unsigned int cmd;
 };
 
 struct lsm_ibpkey_audit {
@@ -78,6 +78,7 @@ struct common_audit_data {
 #define LSM_AUDIT_DATA_NOTIFICATION 16
 #define LSM_AUDIT_DATA_ANONINODE	17
 #define LSM_AUDIT_DATA_NLMSGTYPE	18
+#define LSM_AUDIT_DATA_NS		19
 	union 	{
 		struct path path;
 		struct dentry *dentry;
@@ -100,6 +101,10 @@ struct common_audit_data {
 		int reason;
 		const char *anonclass;
 		u16 nlmsg_type;
+		struct {
+			u32 ns_type;
+			u64 ns_id;
+		} ns;
 	} u;
 	/* this union contains LSM specific data */
 	union {
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 65c9609ec207..af9624c30f99 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -120,26 +120,27 @@ LSM_HOOK(int, -EOPNOTSUPP, inode_init_security, struct inode *inode,
 	 int *xattr_count)
 LSM_HOOK(int, 0, inode_init_security_anon, struct inode *inode,
 	 const struct qstr *name, const struct inode *context_inode)
-LSM_HOOK(int, 0, inode_create, struct inode *dir, struct dentry *dentry,
-	 umode_t mode)
+LSM_HOOK(int, 0, inode_create, struct mnt_idmap *idmap, struct inode *dir,
+	 struct dentry *dentry, umode_t mode)
 LSM_HOOK(void, LSM_RET_VOID, inode_post_create_tmpfile, struct mnt_idmap *idmap,
 	 struct inode *inode)
-LSM_HOOK(int, 0, inode_link, struct dentry *old_dentry, struct inode *dir,
-	 struct dentry *new_dentry)
+LSM_HOOK(int, 0, inode_link, struct mnt_idmap *idmap,
+	 struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
 LSM_HOOK(int, 0, inode_unlink, struct inode *dir, struct dentry *dentry)
-LSM_HOOK(int, 0, inode_symlink, struct inode *dir, struct dentry *dentry,
-	 const char *old_name)
-LSM_HOOK(int, 0, inode_mkdir, struct inode *dir, struct dentry *dentry,
-	 umode_t mode)
+LSM_HOOK(int, 0, inode_symlink, struct mnt_idmap *idmap, struct inode *dir,
+	 struct dentry *dentry, const char *old_name)
+LSM_HOOK(int, 0, inode_mkdir, struct mnt_idmap *idmap, struct inode *dir,
+	 struct dentry *dentry, umode_t mode)
 LSM_HOOK(int, 0, inode_rmdir, struct inode *dir, struct dentry *dentry)
-LSM_HOOK(int, 0, inode_mknod, struct inode *dir, struct dentry *dentry,
-	 umode_t mode, dev_t dev)
+LSM_HOOK(int, 0, inode_mknod, struct mnt_idmap *idmap, struct inode *dir,
+	 struct dentry *dentry, umode_t mode, dev_t dev)
 LSM_HOOK(int, 0, inode_rename, struct inode *old_dir, struct dentry *old_dentry,
 	 struct inode *new_dir, struct dentry *new_dentry)
 LSM_HOOK(int, 0, inode_readlink, struct dentry *dentry)
 LSM_HOOK(int, 0, inode_follow_link, struct dentry *dentry, struct inode *inode,
 	 bool rcu)
-LSM_HOOK(int, 0, inode_permission, struct inode *inode, int mask)
+LSM_HOOK(int, 0, inode_permission, struct mnt_idmap *idmap,
+	 struct inode *inode, int mask)
 LSM_HOOK(int, 0, inode_setattr, struct mnt_idmap *idmap, struct dentry *dentry,
 	 struct iattr *attr)
 LSM_HOOK(void, LSM_RET_VOID, inode_post_setattr, struct mnt_idmap *idmap,
@@ -265,6 +266,9 @@ LSM_HOOK(int, -ENOSYS, task_prctl, int option, unsigned long arg2,
 LSM_HOOK(void, LSM_RET_VOID, task_to_inode, struct task_struct *p,
 	 struct inode *inode)
 LSM_HOOK(int, 0, userns_create, const struct cred *cred)
+LSM_HOOK(int, 0, namespace_init, struct ns_common *ns)
+LSM_HOOK(void, LSM_RET_VOID, namespace_free, struct ns_common *ns)
+LSM_HOOK(int, 0, namespace_install, const struct nsset *nsset, struct ns_common *ns)
 LSM_HOOK(int, 0, ipc_permission, struct kern_ipc_perm *ipcp, short flag)
 LSM_HOOK(void, LSM_RET_VOID, ipc_getlsmprop, struct kern_ipc_perm *ipcp,
 	 struct lsm_prop *prop)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c4488c4a6d8a..13621e9e233e 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -112,6 +112,7 @@ struct lsm_blob_sizes {
 	unsigned int lbs_ipc;
 	unsigned int lbs_key;
 	unsigned int lbs_msg_msg;
+	unsigned int lbs_ns;
 	unsigned int lbs_perf_event;
 	unsigned int lbs_task;
 	unsigned int lbs_xattr_count; /* num xattr slots in new_xattrs array */
diff --git a/include/linux/ns/ns_common_types.h b/include/linux/ns/ns_common_types.h
index 6ed6b497831c..47a5cfe2326a 100644
--- a/include/linux/ns/ns_common_types.h
+++ b/include/linux/ns/ns_common_types.h
@@ -116,6 +116,9 @@ struct ns_common {
 	struct dentry *stashed;
 	const struct proc_ns_operations *ops;
 	unsigned int inum;
+#ifdef CONFIG_SECURITY
+	void *ns_security;
+#endif
 	struct ns_tree;
 	struct rcu_head ns_rcu;
 };
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 705970d07614..5e7b298993ec 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1172,8 +1172,12 @@ struct task_struct {
 	/* Objective and real subjective task credentials (COW): */
 	const struct cred __rcu		*real_cred;
 
-	/* Effective (overridable) subjective task credentials (COW): */
-	const struct cred __rcu		*cred;
+	/*
+	 * Effective (overridable) subjective task credentials (COW).
+	 * Only accessible for the current task and during task creation/freeing.
+	 * This pointer is not managed by RCU!
+	 */
+	const struct cred		*cred;
 
 #ifdef CONFIG_KEYS
 	/* Cached requested key. */
diff --git a/include/linux/security.h b/include/linux/security.h
index 153e9043058f..7bb073f734f6 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -67,6 +67,7 @@ enum fs_value_type;
 struct watch;
 struct watch_notification;
 struct lsm_ctx;
+struct nsset;
 
 /* Default (no) options for the capable function */
 #define CAP_OPT_NONE 0x0
@@ -80,6 +81,7 @@ struct lsm_ctx;
 
 struct ctl_table;
 struct audit_krule;
+struct ns_common;
 struct user_namespace;
 struct timezone;
 
@@ -404,24 +406,28 @@ int security_inode_init_security(struct inode *inode, struct inode *dir,
 int security_inode_init_security_anon(struct inode *inode,
 				      const struct qstr *name,
 				      const struct inode *context_inode);
-int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode);
+int security_inode_create(struct mnt_idmap *idmap, struct inode *dir,
+			  struct dentry *dentry, umode_t mode);
 void security_inode_post_create_tmpfile(struct mnt_idmap *idmap,
 					struct inode *inode);
-int security_inode_link(struct dentry *old_dentry, struct inode *dir,
-			 struct dentry *new_dentry);
+int security_inode_link(struct mnt_idmap *idmap, struct dentry *old_dentry,
+			struct inode *dir, struct dentry *new_dentry);
 int security_inode_unlink(struct inode *dir, struct dentry *dentry);
-int security_inode_symlink(struct inode *dir, struct dentry *dentry,
-			   const char *old_name);
-int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
+int security_inode_symlink(struct mnt_idmap *idmap, struct inode *dir,
+			   struct dentry *dentry, const char *old_name);
+int security_inode_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+			 struct dentry *dentry, umode_t mode);
 int security_inode_rmdir(struct inode *dir, struct dentry *dentry);
-int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev);
+int security_inode_mknod(struct mnt_idmap *idmap, struct inode *dir,
+			 struct dentry *dentry, umode_t mode, dev_t dev);
 int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
 			  struct inode *new_dir, struct dentry *new_dentry,
 			  unsigned int flags);
 int security_inode_readlink(struct dentry *dentry);
 int security_inode_follow_link(struct dentry *dentry, struct inode *inode,
 			       bool rcu);
-int security_inode_permission(struct inode *inode, int mask);
+int security_inode_permission(struct mnt_idmap *idmap, struct inode *inode,
+			      int mask);
 int security_inode_setattr(struct mnt_idmap *idmap,
 			   struct dentry *dentry, struct iattr *attr);
 void security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
@@ -540,6 +546,9 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 			unsigned long arg4, unsigned long arg5);
 void security_task_to_inode(struct task_struct *p, struct inode *inode);
 int security_create_user_ns(const struct cred *cred);
+int security_namespace_init(struct ns_common *ns);
+void security_namespace_free(struct ns_common *ns);
+int security_namespace_install(const struct nsset *nsset, struct ns_common *ns);
 int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
 void security_ipc_getlsmprop(struct kern_ipc_perm *ipcp, struct lsm_prop *prop);
 int security_msg_msg_alloc(struct msg_msg *msg);
@@ -902,9 +911,10 @@ static inline int security_inode_init_security_anon(struct inode *inode,
 	return 0;
 }
 
-static inline int security_inode_create(struct inode *dir,
-					 struct dentry *dentry,
-					 umode_t mode)
+static inline int security_inode_create(struct mnt_idmap *idmap,
+					struct inode *dir,
+					struct dentry *dentry,
+					umode_t mode)
 {
 	return 0;
 }
@@ -913,9 +923,10 @@ static inline void
 security_inode_post_create_tmpfile(struct mnt_idmap *idmap, struct inode *inode)
 { }
 
-static inline int security_inode_link(struct dentry *old_dentry,
-				       struct inode *dir,
-				       struct dentry *new_dentry)
+static inline int security_inode_link(struct mnt_idmap *idmap,
+				      struct dentry *old_dentry,
+				      struct inode *dir,
+				      struct dentry *new_dentry)
 {
 	return 0;
 }
@@ -926,16 +937,18 @@ static inline int security_inode_unlink(struct inode *dir,
 	return 0;
 }
 
-static inline int security_inode_symlink(struct inode *dir,
-					  struct dentry *dentry,
-					  const char *old_name)
+static inline int security_inode_symlink(struct mnt_idmap *idmap,
+					 struct inode *dir,
+					 struct dentry *dentry,
+					 const char *old_name)
 {
 	return 0;
 }
 
-static inline int security_inode_mkdir(struct inode *dir,
-					struct dentry *dentry,
-					int mode)
+static inline int security_inode_mkdir(struct mnt_idmap *idmap,
+				       struct inode *dir,
+				       struct dentry *dentry,
+				       int mode)
 {
 	return 0;
 }
@@ -946,9 +959,10 @@ static inline int security_inode_rmdir(struct inode *dir,
 	return 0;
 }
 
-static inline int security_inode_mknod(struct inode *dir,
-					struct dentry *dentry,
-					int mode, dev_t dev)
+static inline int security_inode_mknod(struct mnt_idmap *idmap,
+				       struct inode *dir,
+				       struct dentry *dentry,
+				       int mode, dev_t dev)
 {
 	return 0;
 }
@@ -974,7 +988,8 @@ static inline int security_inode_follow_link(struct dentry *dentry,
 	return 0;
 }
 
-static inline int security_inode_permission(struct inode *inode, int mask)
+static inline int security_inode_permission(struct mnt_idmap *idmap,
+					    struct inode *inode, int mask)
 {
 	return 0;
 }
@@ -1431,6 +1446,21 @@ static inline int security_create_user_ns(const struct cred *cred)
 	return 0;
 }
 
+static inline int security_namespace_init(struct ns_common *ns)
+{
+	return 0;
+}
+
+static inline void security_namespace_free(struct ns_common *ns)
+{
+}
+
+static inline int security_namespace_install(const struct nsset *nsset,
+					     struct ns_common *ns)
+{
+	return 0;
+}
+
 static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
 					  short flag)
 {