From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754646AbbHBANP (ORCPT ); Sat, 1 Aug 2015 20:13:15 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35929 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751703AbbHBAJr (ORCPT ); Sat, 1 Aug 2015 20:09:47 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Hannes Frederic Sowa" , "Mark Salyzyn" Date: Sun, 02 Aug 2015 01:02:38 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 134/164] unix/caif: sk_socket can disappear when state is unlocked In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.70-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mark Salyzyn [ Upstream commit b48732e4a48d80ed4a14812f0bab09560846514e ] got a rare NULL pointer dereference in clear_bit Signed-off-by: Mark Salyzyn Acked-by: Hannes Frederic Sowa ---- v2: switch to sock_flag(sk, SOCK_DEAD) and added net/caif/caif_socket.c v3: return -ECONNRESET in upstream caller of wait function for SOCK_DEAD Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- net/caif/caif_socket.c | 8 ++++++++ net/unix/af_unix.c | 8 ++++++++ 2 files changed, 16 insertions(+) --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -366,6 +366,10 @@ static long caif_stream_data_wait(struct release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); + + if (sock_flag(sk, SOCK_DEAD)) + break; + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } @@ -410,6 +414,10 @@ static int caif_stream_recvmsg(struct ki struct sk_buff *skb; lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD)) { + err = -ECONNRESET; + goto unlock; + } skb = skb_dequeue(&sk->sk_receive_queue); caif_check_flow_release(sk); --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1870,6 +1870,10 @@ static long unix_stream_data_wait(struct unix_state_unlock(sk); timeo = schedule_timeout(timeo); unix_state_lock(sk); + + if (sock_flag(sk, SOCK_DEAD)) + break; + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } @@ -1930,6 +1934,10 @@ static int unix_stream_recvmsg(struct ki struct sk_buff *skb; unix_state_lock(sk); + if (sock_flag(sk, SOCK_DEAD)) { + err = -ECONNRESET; + goto unlock; + } skb = skb_peek(&sk->sk_receive_queue); if (skb == NULL) { unix_sk(sk)->recursion_level = 0;