[PATCH 3.12 09/33] net: pktgen: fix race between pktgen_thread_worker() and kthread_stop()

[Jiri Slaby]

From: Oleg Nesterov <oleg@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

[ Upstream commit fecdf8be2d91e04b0a9a4f79ff06499a36f5d14f ]

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 <oleg@xxxxxxxxxx>
Reported-by: Jan Stancek <jstancek@xxxxxxxxxx>
Reported-by: Marcelo Leitner <mleitner@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 net/core/pktgen.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index a104ba3c5768..cea47344d535 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -3423,8 +3423,10 @@ 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);
-- 
2.5.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/