From patchwork Wed Mar 2 06:34:47 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerrit Renker X-Patchwork-Id: 85032 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 89E411007D2 for ; Wed, 2 Mar 2011 17:35:07 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751499Ab1CBGfA (ORCPT ); Wed, 2 Mar 2011 01:35:00 -0500 Received: from dee.erg.abdn.ac.uk ([139.133.204.82]:53089 "EHLO erg.abdn.ac.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750918Ab1CBGe7 (ORCPT ); Wed, 2 Mar 2011 01:34:59 -0500 Received: from laptev.erg.abdn.ac.uk (Debian-exim@ra-gerrit.erg.abdn.ac.uk [139.133.204.38]) by erg.abdn.ac.uk (8.13.4/8.13.4) with ESMTP id p226YlTr004937 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Wed, 2 Mar 2011 06:34:47 GMT Received: from gerrit by laptev.erg.abdn.ac.uk with local (Exim 4.69) (envelope-from ) id 1Pufe3-0001L0-AF; Wed, 02 Mar 2011 07:34:47 +0100 Date: Wed, 2 Mar 2011 07:34:47 +0100 From: Gerrit Renker To: "David S. Miller" , netdev@vger.kernel.org Cc: Johan Hovold Subject: [Bug-Fix][Patch 1/1] dccp: fix oops on Reset after close Message-ID: <20110302063447.GB4902@gerrit.erg.abdn.ac.uk> Mail-Followup-To: Gerrit Renker , "David S. Miller" , netdev@vger.kernel.org, Johan Hovold MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) X-ERG-MailScanner: Found to be clean X-ERG-MailScanner-From: gerrit@erg.abdn.ac.uk X-Spam-Status: No Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Dave, could you please apply the below bug fix for a condition where a simple packet reception can trigger oops. >>>>>>>>>>>>>>>>>>>>>>>>>>>>> Patch <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< dccp: fix oops on Reset after close This fixes a bug in the order of dccp_rcv_state_process() that still permitted reception even after closing the socket. A Reset after close thus causes a NULL pointer dereference by not preventing operations on an already torn-down socket. dccp_v4_do_rcv() | | state other than OPEN v dccp_rcv_state_process() | | DCCP_PKT_RESET v dccp_rcv_reset() | v dccp_time_wait() WARNING: at net/ipv4/inet_timewait_sock.c:141 __inet_twsk_hashdance+0x48/0x128() Modules linked in: arc4 ecb carl9170 rt2870sta(C) mac80211 r8712u(C) crc_ccitt ah [] (unwind_backtrace+0x0/0xec) from [] (warn_slowpath_common) [] (warn_slowpath_common+0x4c/0x64) from [] (warn_slowpath_n) [] (warn_slowpath_null+0x1c/0x24) from [] (__inet_twsk_hashd) [] (__inet_twsk_hashdance+0x48/0x128) from [] (dccp_time_wai) [] (dccp_time_wait+0x40/0xc8) from [] (dccp_rcv_state_proces) [] (dccp_rcv_state_process+0x120/0x538) from [] (dccp_v4_do_) [] (dccp_v4_do_rcv+0x11c/0x14c) from [] (release_sock+0xac/0) [] (release_sock+0xac/0x110) from [] (dccp_close+0x28c/0x380) [] (dccp_close+0x28c/0x380) from [] (inet_release+0x64/0x70) The fix is by testing the socket state first. Receiving a packet in Closed state now also produces the required "No connection" Reset reply of RFC 4340, 8.3.1. Reported-and-tested-by: Johan Hovold Cc: stable@kernel.org Signed-off-by: Gerrit Renker --- net/dccp/input.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -614,6 +614,9 @@ int dccp_rcv_state_process(struct sock * /* Caller (dccp_v4_do_rcv) will send Reset */ dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; return 1; + } else if (sk->sk_state == DCCP_CLOSED) { + dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; + return 1; } if (sk->sk_state != DCCP_REQUESTING && sk->sk_state != DCCP_RESPOND) { @@ -668,10 +671,6 @@ int dccp_rcv_state_process(struct sock * } switch (sk->sk_state) { - case DCCP_CLOSED: - dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; - return 1; - case DCCP_REQUESTING: queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); if (queued >= 0)