From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753629AbbEZPXZ (ORCPT ); Tue, 26 May 2015 11:23:25 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:33068 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103AbbEZPXX (ORCPT ); Tue, 26 May 2015 11:23:23 -0400 From: Mark Salyzyn To: hannes@redhat.com, linux-kernel@vger.kernel.org Cc: Mark Salyzyn , Dmitry Tarnyagin , "David S. Miller" , Al Viro , David Howells , Ying Xue , Christoph Hellwig , netdev@vger.kernel.org Subject: [PATCH v3] net/unix: sk_socket can disappear when state is unlocked Date: Tue, 26 May 2015 08:22:19 -0700 Message-Id: <1432653777-13799-1-git-send-email-salyzyn@android.com> X-Mailer: git-send-email 2.2.0.rc0.207.ga3a616c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org got a rare NULL pointer dereference in clear_bit Signed-off-by: Mark Salyzyn ---- 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 --- net/caif/caif_socket.c | 8 ++++++++ net/unix/af_unix.c | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 4ec0c80..112ad78 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -330,6 +330,10 @@ static long caif_stream_data_wait(struct sock *sk, long timeo) 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); } @@ -373,6 +377,10 @@ static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg, 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); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 5266ea7..0643059 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1880,6 +1880,10 @@ static long unix_stream_data_wait(struct sock *sk, long timeo, unix_state_unlock(sk); timeo = freezable_schedule_timeout(timeo); unix_state_lock(sk); + + if (sock_flag(sk, SOCK_DEAD)) + break; + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } @@ -1939,6 +1943,10 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, struct sk_buff *skb, *last; unix_state_lock(sk); + if (sock_flag(sk, SOCK_DEAD)) { + err = -ECONNRESET; + goto unlock; + } last = skb = skb_peek(&sk->sk_receive_queue); again: if (skb == NULL) { -- 2.2.0.rc0.207.ga3a616c