Merge tag 'selinux-pr-20210830' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux update from Paul Moore:
 "We've got an unusually small SELinux pull request for v5.15 that
  consists of only one (?!) patch that is really pretty minor when you
  look at it.

  Unsurprisingly it passes all of our tests and merges cleanly on top of
  your tree right now, please merge this for v5.15"

* tag 'selinux-pr-20210830' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: return early for possible NULL audit buffers

security/selinux/hooks.c

@@ -3325,6 +3325,8 @@ static int selinux_inode_setxattr(struct user_namespace *mnt_userns,
 			}
 			ab = audit_log_start(audit_context(),
 					     GFP_ATOMIC, AUDIT_SELINUX_ERR);
+			if (!ab)
+				return rc;
 			audit_log_format(ab, "op=setxattr invalid_context=");
 			audit_log_n_untrustedstring(ab, value, audit_size);
 			audit_log_end(ab);
@@ -6552,6 +6554,8 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
 				ab = audit_log_start(audit_context(),
 						     GFP_ATOMIC,
 						     AUDIT_SELINUX_ERR);
+				if (!ab)
+					return error;
 				audit_log_format(ab, "op=fscreate invalid_context=");
 				audit_log_n_untrustedstring(ab, value, audit_size);
 				audit_log_end(ab);

security/selinux/ss/services.c

@@ -1673,6 +1673,8 @@ static int compute_sid_handle_invalid_context(
 	if (context_struct_to_string(policydb, newcontext, &n, &nlen))
 		goto out;
 	ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
+	if (!ab)
+		goto out;
 	audit_log_format(ab,
 			 "op=security_compute_sid invalid_context=");
 	/* no need to record the NUL with untrusted strings */