Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org,
        Eric Van Hensbergen <ericvh@gmail.com>,
        Ron Minnich <rminnich@sandia.gov>,
        Latchesar Ionkov <lucho@ionkov.net>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tomas Bortoli <tomasbortoli@gmail.com>,
        syzbot+39749ed7d9ef6dfb23f6@syzkaller.appspotmail.com,
        Yiwen Jiang <jiangyiwen@huwei.com>,
        Dominique Martinet <dominique.martinet@cea.fr>
Subject: [PATCH 4.4 12/47] net/9p/trans_fd.c: fix race-condition by flushing workqueue before the kfree()
Date:   Fri,  7 Sep 2018 23:10:08 +0200
Message-Id: <20180907210905.598511701@linuxfoundation.org>
In-Reply-To: <20180907210904.607934824@linuxfoundation.org>
References: <20180907210904.607934824@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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

------------------

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>
Cc: stable@vger.kernel.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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);
 }
 
 /**