From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932962Ab1DYUwr (ORCPT ); Mon, 25 Apr 2011 16:52:47 -0400 Received: from 1wt.eu ([62.212.114.60]:34040 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932086Ab1DYUYX (ORCPT ); Mon, 25 Apr 2011 16:24:23 -0400 Message-Id: <20110425200235.904204472@pcw.home.local> User-Agent: quilt/0.48-1 Date: Mon, 25 Apr 2011 22:03:39 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org Cc: Gerrit Renker , "David S. Miller" , Greg Kroah-Hartman Subject: [PATCH 067/173] dccp: fix oops on Reset after close In-Reply-To: <46075c3a3ef08be6d70339617d6afc98@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27.59-stable review patch. If anyone has any objections, please let us know. ------------------ From: Gerrit Renker commit 720dc34bbbe9493c7bd48b2243058b4e447a929d upstream. 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 Signed-off-by: Gerrit Renker Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dccp/input.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -616,6 +616,9 @@ 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) { @@ -678,10 +681,6 @@ 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)