audit: move calcs after alloc and check when logging set loginuid

Move the calculations of values after the allocation in case the
allocation fails.  This avoids wasting effort in the rare case that it
fails, but more importantly saves us extra logic to release the tty
ref.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 71e14d836e69f84d4e53e52a8e9d7280914f930a..33dafa70229d53206e1c1541640838920283150c 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1985,14 +1985,15 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
        if (!audit_enabled)
                return;
 
+       ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
+       if (!ab)
+               return;
+
        uid = from_kuid(&init_user_ns, task_uid(current));
        oldloginuid = from_kuid(&init_user_ns, koldloginuid);
        loginuid = from_kuid(&init_user_ns, kloginuid),
        tty = audit_get_tty(current);
 
-       ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
-       if (!ab)
-               return;
        audit_log_format(ab, "pid=%d uid=%u", task_pid_nr(current), uid);
        audit_log_task_context(ab);
        audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",