net: pktgen: fix race between pktgen_thread_worker() and kthread_stop()

[ Upstream commit fecdf8b ] pktgen_thread_worker() is obviously racy, kthread_stop() can come between the kthread_should_stop() check and set_current_state(). Signed-off-by: Oleg Nesterov <[email protected]> Reported-by: Jan Stancek <[email protected]> Reported-by: Marcelo Leitner <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
nemunaire · Sep 27, 2015 · d69e9e1 · d69e9e1
1 parent 4192b62
commit d69e9e1
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
@@ -3490,8 +3490,10 @@ static int pktgen_thread_worker(void *arg)
 	pktgen_rem_thread(t);
 
 	/* Wait for kthread_stop */
-	while (!kthread_should_stop()) {
+	for (;;) {
 		set_current_state(TASK_INTERRUPTIBLE);
+		if (kthread_should_stop())
+			break;
 		schedule();
 	}
 	__set_current_state(TASK_RUNNING);