From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59480 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754486AbdERMWU (ORCPT ); Thu, 18 May 2017 08:22:20 -0400 Subject: Patch "af_unix: Guard against other == sk in unix_dgram_sendmsg" has been added to the 3.18-stable tree To: rweikusat@mobileactivedefense.com, amit.pundir@linaro.org, davem@davemloft.net, gregkh@linuxfoundation.org, pmhahn@pmhahn.de Cc: , From: Date: Thu, 18 May 2017 14:22:10 +0200 Message-ID: <149511013060202@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled af_unix: Guard against other == sk in unix_dgram_sendmsg to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: af_unix-guard-against-other-sk-in-unix_dgram_sendmsg.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From a5527dda344fff0514b7989ef7a755729769daa1 Mon Sep 17 00:00:00 2001 From: Rainer Weikusat Date: Thu, 11 Feb 2016 19:37:27 +0000 Subject: af_unix: Guard against other == sk in unix_dgram_sendmsg From: Rainer Weikusat commit a5527dda344fff0514b7989ef7a755729769daa1 upstream. The unix_dgram_sendmsg routine use the following test if (unlikely(unix_peer(other) != sk && unix_recvq_full(other))) { to determine if sk and other are in an n:1 association (either established via connect or by using sendto to send messages to an unrelated socket identified by address). This isn't correct as the specified address could have been bound to the sending socket itself or because this socket could have been connected to itself by the time of the unix_peer_get but disconnected before the unix_state_lock(other). In both cases, the if-block would be entered despite other == sk which might either block the sender unintentionally or lead to trying to unlock the same spin lock twice for a non-blocking send. Add a other != sk check to guard against this. Fixes: 7d267278a9ec ("unix: avoid use-after-free in ep_remove_wait_queue") Reported-By: Philipp Hahn Signed-off-by: Rainer Weikusat Tested-by: Philipp Hahn Signed-off-by: David S. Miller Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- net/unix/af_unix.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1722,7 +1722,12 @@ restart_locked: goto out_unlock; } - if (unlikely(unix_peer(other) != sk && unix_recvq_full(other))) { + /* other == sk && unix_peer(other) != sk if + * - unix_peer(sk) == NULL, destination address bound to sk + * - unix_peer(sk) == sk by time of get but disconnected before lock + */ + if (other != sk && + unlikely(unix_peer(other) != sk && unix_recvq_full(other))) { if (timeo) { timeo = unix_wait_for_peer(other, timeo); Patches currently in stable-queue which might be from rweikusat@mobileactivedefense.com are queue-3.18/af_unix-guard-against-other-sk-in-unix_dgram_sendmsg.patch