Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751385AbaKFGdn (ORCPT ); Thu, 6 Nov 2014 01:33:43 -0500 Received: from antispam.ahnlab.com ([210.121.169.55]:59415 "EHLO antispam.ahnlab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750768AbaKFGdm (ORCPT ); Thu, 6 Nov 2014 01:33:42 -0500 X-Original-SENDERIP: 172.16.11.209 X-Original-MAILFROM: suhyun.park@ahnlab.com From: Su-Hyun Park To: Stephen Hemminger , "David S. Miller" CC: , , , Su-Hyun Park Subject: [PATCH] bridge: missing null bridge device check causing null pointer dereference (bugfix) Date: Thu, 6 Nov 2014 15:26:32 +0900 Message-ID: <1415255192-13584-1-git-send-email-suhyun.park@ahnlab.com> X-Mailer: git-send-email 1.8.1.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.20.32.23] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org the bridge device can be null if the bridge is being deleted while processing the packet, which causes the null pointer dereference in switch statement. crash dump snippet: <1>BUG: unable to handle kernel NULL pointer dereference at 0000000000000021 <1>IP: [] br_handle_frame+0xe6/0x270 <0>Code: 4c 0f 44 f0 89 f8 66 33 15 32 52 24 00 66 33 05 29 52 24 00 09 c2 89 f0 66 33 05 22 52 24 00 80 e4 f0 66 09 c2 0f 84 eb 00 00 00 <41> 0f b6 46 21 3c 02 74 61 3c 03 74 1d 48 89 df e8 d5 bc f0 ff --- net/bridge/br_input.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 6fd5522..7e899ca 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -176,6 +176,8 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb) return RX_HANDLER_CONSUMED; p = br_port_get_rcu(skb->dev); + if (!p) + goto drop; if (unlikely(is_link_local_ether_addr(dest))) { u16 fwd_mask = p->br->group_fwd_mask_required; -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/