Patch "net: pktgen: fix race between pktgen_thread_worker() and kthread_stop()" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-pktgen-fix-race-between-pktgen_thread_worker-and-kthread_stop.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Sep 26 11:13:07 PDT 2015
From: Oleg Nesterov <oleg@redhat.com>
Date: Wed, 8 Jul 2015 21:42:11 +0200
Subject: net: pktgen: fix race between pktgen_thread_worker() and kthread_stop()

From: Oleg Nesterov <oleg@redhat.com>

[ 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@redhat.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Reported-by: Marcelo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/pktgen.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -3490,8 +3490,10 @@ static int pktgen_thread_worker(void *ar
 	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);


Patches currently in stable-queue which might be from oleg@redhat.com are

queue-4.1/net-pktgen-fix-race-between-pktgen_thread_worker-and-kthread_stop.patch