[PATCH 3.16 129/328] net/9p/trans_fd.c: fix race-condition by flushing workqueue before the kfree()

Ben Hutchings
2018-12-09T22:04:51Z

From: Tomas Bortoli <tomasbortoli@gmail.com>

commit 430ac66eb4c5b5c4eb846b78ebf65747510b30f1 upstream.

The patch adds the flush in p9_mux_poll_stop() as it the function used by
p9_conn_destroy(), in turn called by p9_fd_close() to stop the async
polling associated with the data regarding the connection.

Link: http://lkml.kernel.org/r/20180720092730.27104-1-tomasbortoli@gmail.com
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+39749ed7d9ef6dfb23f6@syzkaller.appspotmail.com
To: Eric Van Hensbergen <ericvh@gmail.com>
To: Ron Minnich <rminnich@sandia.gov>
To: Latchesar Ionkov <lucho@ionkov.net>
Cc: Yiwen Jiang <jiangyiwen@huwei.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/9p/trans_fd.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -185,6 +185,8 @@ static void p9_mux_poll_stop(struct p9_c
spin_lock_irqsave(&p9_poll_lock, flags);
list_del_init(&m->poll_pending_link);
spin_unlock_irqrestore(&p9_poll_lock, flags);
+
+ flush_work(&p9_poll_work);
}

/**