Merge tag 'selinux-pr-20220110' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "Nothing too significant, but five SELinux patches for v5.17 that do
  the following:

   - Harden the code through additional use of the struct_size() macro

   - Plug some memory leaks

   - Clean up the code via removal of the security_add_mnt_opt() LSM
     hook and minor tweaks to selinux_add_opt()

   - Rename security_task_getsecid_subj() to better reflect its actual
     behavior/use - now called security_current_getsecid_subj()"

* tag 'selinux-pr-20220110' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: minor tweaks to selinux_add_opt()
  selinux: fix potential memleak in selinux_add_opt()
  security,selinux: remove security_add_mnt_opt()
  selinux: Use struct_size() helper in kmalloc()
  lsm: security_task_getsecid_subj() -> security_current_getsecid_subj()

3 files changed, 13 insertions, 5 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 4cebadb5f30d..79c146184729 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2131,7 +2131,7 @@ int audit_log_task_context(struct audit_buffer *ab)
 	int error;
 	u32 sid;
 
-	security_task_getsecid_subj(current, &sid);
+	security_current_getsecid_subj(&sid);
 	if (!sid)
 		return 0;
 
@@ -2352,7 +2352,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 			audit_sig_uid = auid;
 		else
 			audit_sig_uid = uid;
-		security_task_getsecid_subj(current, &audit_sig_sid);
+		security_current_getsecid_subj(&audit_sig_sid);
 	}
 
 	return audit_signal_info_syscall(t);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index d75acb014ccd..4173e771650c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1368,8 +1368,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_rule) {
-					security_task_getsecid_subj(current,
-								    &sid);
+					security_current_getsecid_subj(&sid);
 					result = security_audit_rule_match(sid,
 						   f->type, f->op, f->lsm_rule);
 				}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b517947bfa48..fce5d43a933f 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -666,7 +666,16 @@ static int audit_filter_rules(struct task_struct *tsk,
 			   logged upon error */
 			if (f->lsm_rule) {
 				if (need_sid) {
-					security_task_getsecid_subj(tsk, &sid);
+					/* @tsk should always be equal to
+					 * @current with the exception of
+					 * fork()/copy_process() in which case
+					 * the new @tsk creds are still a dup
+					 * of @current's creds so we can still
+					 * use security_current_getsecid_subj()
+					 * here even though it always refs
+					 * @current's creds
+					 */
+					security_current_getsecid_subj(&sid);
 					need_sid = 0;
 				}
 				result = security_audit_rule_match(sid, f->type,