1 files changed, 16 insertions, 2 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 8f3debc77c5b..c89821b69ae3 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -24,6 +24,7 @@
 #include <linux/ptrace.h>
 #include <linux/posix-timers.h>
 #include <linux/signal.h>
+#include <linux/audit.h>
 #include <asm/param.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -522,7 +523,16 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
 {
         int sig = 0;
 
-        sig = next_signal(pending, mask);
+        /* SIGKILL must have priority, otherwise it is quite easy
+         * to create an unkillable process, sending sig < SIGKILL
+         * to self */
+        if (unlikely(sigismember(&pending->signal, SIGKILL))) {
+                if (!sigismember(mask, SIGKILL))
+                        sig = SIGKILL;
+        }
+
+        if (likely(!sig))
+                sig = next_signal(pending, mask);
         if (sig) {
                 if (current->notifier) {
                         if (sigismember(current->notifier_mask, sig)) {
@@ -658,7 +668,11 @@ static int check_kill_permission(int sig, struct siginfo *info,
             && (current->uid ^ t->suid) && (current->uid ^ t->uid)
             && !capable(CAP_KILL))
                 return error;
-        return security_task_kill(t, info, sig);
+
+        error = security_task_kill(t, info, sig);
+        if (!error)
+                audit_signal_info(sig, t); /* Let audit system see the signal */
+        return error;
 }
 
 /* forward decl */