Merge tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:

 - Add support for measuring the SELinux state and policy capabilities
   using IMA.

 - A handful of SELinux/NFS patches to compare the SELinux state of one
   mount with a set of mount options. Olga goes into more detail in the
   patch descriptions, but this is important as it allows more
   flexibility when using NFS and SELinux context mounts.

 - Properly differentiate between the subjective and objective LSM
   credentials; including support for the SELinux and Smack. My clumsy
   attempt at a proper fix for AppArmor didn't quite pass muster so John
   is working on a proper AppArmor patch, in the meantime this set of
   patches shouldn't change the behavior of AppArmor in any way. This
   change explains the bulk of the diffstat beyond security/.

 - Fix a problem where we were not properly terminating the permission
   list for two SELinux object classes.

* tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: add proper NULL termination to the secclass_map permissions
  smack: differentiate between subjective and objective task credentials
  selinux: clarify task subjective and objective credentials
  lsm: separate security_task_getsecid() into subjective and objective variants
  nfs: account for selinux security context when deciding to share superblock
  nfs: remove unneeded null check in nfs_fill_super()
  lsm,selinux: add new hook to compare new mount to an existing mount
  selinux: fix misspellings using codespell tool
  selinux: fix misspellings using codespell tool
  selinux: measure state and policy capabilities
  selinux: Allow context mounts for unpriviliged overlayfs

5 files changed, 38 insertions, 7 deletions

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 4c6350503697..ac0e5f97d7d8 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -140,7 +140,7 @@ struct cred {
 	struct key	*request_key_auth; /* assumed request_key authority */
 #endif
 #ifdef CONFIG_SECURITY
-	void		*security;	/* subjective LSM security */
+	void		*security;	/* LSM security */
 #endif
 	struct user_struct *user;	/* real user ID subscription */
 	struct user_namespace *user_ns; /* user_ns the caps and keyrings are relative to. */
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 477a597db013..61f04f7dc1a4 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -62,6 +62,7 @@ LSM_HOOK(int, 0, sb_alloc_security, struct super_block *sb)
 LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb)
 LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
 LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
+LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
 LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
 LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
 LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
@@ -203,7 +204,10 @@ LSM_HOOK(int, 0, task_fix_setgid, struct cred *new, const struct cred * old,
 LSM_HOOK(int, 0, task_setpgid, struct task_struct *p, pid_t pgid)
 LSM_HOOK(int, 0, task_getpgid, struct task_struct *p)
 LSM_HOOK(int, 0, task_getsid, struct task_struct *p)
-LSM_HOOK(void, LSM_RET_VOID, task_getsecid, struct task_struct *p, u32 *secid)
+LSM_HOOK(void, LSM_RET_VOID, task_getsecid_subj,
+	 struct task_struct *p, u32 *secid)
+LSM_HOOK(void, LSM_RET_VOID, task_getsecid_obj,
+	 struct task_struct *p, u32 *secid)
 LSM_HOOK(int, 0, task_setnice, struct task_struct *p, int nice)
 LSM_HOOK(int, 0, task_setioprio, struct task_struct *p, int ioprio)
 LSM_HOOK(int, 0, task_getioprio, struct task_struct *p)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index fb7f3193753d..ba2ccd950833 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -142,6 +142,12 @@
  *	@orig the original mount data copied from userspace.
  *	@copy copied data which will be passed to the security module.
  *	Returns 0 if the copy was successful.
+ * @sb_mnt_opts_compat:
+ *	Determine if the new mount options in @mnt_opts are allowed given
+ *	the existing mounted filesystem at @sb.
+ *	@sb superblock being compared
+ *	@mnt_opts new mount options
+ *	Return 0 if options are compatible.
  * @sb_remount:
  *	Extracts security system specific mount options and verifies no changes
  *	are being made to those options.
@@ -707,9 +713,15 @@
  *	@p.
  *	@p contains the task_struct for the process.
  *	Return 0 if permission is granted.
- * @task_getsecid:
- *	Retrieve the security identifier of the process @p.
- *	@p contains the task_struct for the process and place is into @secid.
+ * @task_getsecid_subj:
+ *	Retrieve the subjective security identifier of the task_struct in @p
+ *	and return it in @secid.  Special care must be taken to ensure that @p
+ *	is the either the "current" task, or the caller has exclusive access
+ *	to @p.
+ *	In case of failure, @secid will be set to zero.
+ * @task_getsecid_obj:
+ *	Retrieve the objective security identifier of the task_struct in @p
+ *	and return it in @secid.
  *	In case of failure, @secid will be set to zero.
  *
  * @task_setnice:
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 6f76b32a0238..a28d71b45b5f 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -256,6 +256,7 @@ struct nfs_server {
 
 	/* User namespace info */
 	const struct cred	*cred;
+	bool			has_sec_mnt_opts;
 };
 
 /* Server capabilities */
diff --git a/include/linux/security.h b/include/linux/security.h
index 8aeebd6646dc..9aeda3f9e838 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -294,6 +294,7 @@ int security_sb_alloc(struct super_block *sb);
 void security_sb_free(struct super_block *sb);
 void security_free_mnt_opts(void **mnt_opts);
 int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
+int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
 int security_sb_remount(struct super_block *sb, void *mnt_opts);
 int security_sb_kern_mount(struct super_block *sb);
 int security_sb_show_options(struct seq_file *m, struct super_block *sb);
@@ -414,7 +415,8 @@ 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(struct task_struct *p, u32 *secid);
+void security_task_getsecid_subj(struct task_struct *p, u32 *secid);
+void security_task_getsecid_obj(struct task_struct *p, u32 *secid);
 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);
@@ -646,6 +648,13 @@ static inline int security_sb_remount(struct super_block *sb,
 	return 0;
 }
 
+static inline int security_sb_mnt_opts_compat(struct super_block *sb,
+					      void *mnt_opts)
+{
+	return 0;
+}
+
+
 static inline int security_sb_kern_mount(struct super_block *sb)
 {
 	return 0;
@@ -1098,7 +1107,12 @@ static inline int security_task_getsid(struct task_struct *p)
 	return 0;
 }
 
-static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid_subj(struct task_struct *p, u32 *secid)
+{
+	*secid = 0;
+}
+
+static inline void security_task_getsecid_obj(struct task_struct *p, u32 *secid)
 {
 	*secid = 0;
 }