From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH] l2tp: fix l2tp_recv_dequeue() Date: Wed, 02 Nov 2011 23:53:04 +0100 Message-ID: <4EB1C9D0.9000001@gmail.com> References: <1320186916.4728.1.camel@edumazet-laptop> <1320217652.30178.1.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Misha Labjuk Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:41688 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750889Ab1KBWxM (ORCPT ); Wed, 2 Nov 2011 18:53:12 -0400 Received: by wyh15 with SMTP id 15so651259wyh.19 for ; Wed, 02 Nov 2011 15:53:10 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 02/11/2011 23:35, Misha Labjuk wrote: > Thanks!! Panic disappeared. > > Thanks ! Here is the official submission then :) [PATCH] l2tp: fix l2tp_recv_dequeue() Misha Labjuk reported panics occurring in l2tp_recv_dequeue() If we release reorder_q.lock, we must not keep a dangling pointer (tmp) and restart the whole loop. Reported-by: Misha Labjuk Tested-by: Misha Labjuk Signed-off-by: Eric Dumazet --- net/l2tp/l2tp_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 34b2dde..bf8d50c 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -397,6 +397,7 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) * expect to send up next, dequeue it and any other * in-sequence packets behind it. */ +start: spin_lock_bh(&session->reorder_q.lock); skb_queue_walk_safe(&session->reorder_q, skb, tmp) { if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { @@ -433,7 +434,7 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) */ spin_unlock_bh(&session->reorder_q.lock); l2tp_recv_dequeue_skb(session, skb); - spin_lock_bh(&session->reorder_q.lock); + goto start; } out: