Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753852AbdCFJZV (ORCPT ); Mon, 6 Mar 2017 04:25:21 -0500 Received: from mx2.suse.de ([195.135.220.15]:37222 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753276AbdCFJNv (ORCPT ); Mon, 6 Mar 2017 04:13:51 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Maxime Jayat , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 076/113] net: socket: fix recvmmsg not returning error from sock_error Date: Mon, 6 Mar 2017 10:11:40 +0100 Message-Id: X-Mailer: git-send-email 2.12.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1538 Lines: 49 From: Maxime Jayat 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit e623a9e9dec29ae811d11f83d0074ba254aba374 ] Commit 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path"), changed the exit path of recvmmsg to always return the datagrams variable and modified the error paths to set the variable to the error code returned by recvmsg if necessary. However in the case sock_error returned an error, the error code was then ignored, and recvmmsg returned 0. Change the error path of recvmmsg to correctly return the error code of sock_error. The bug was triggered by using recvmmsg on a CAN interface which was not up. Linux 4.6 and later return 0 in this case while earlier releases returned -ENETDOWN. Fixes: 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path") Signed-off-by: Maxime Jayat Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/socket.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/socket.c b/net/socket.c index 64c47cd62e14..bc3f3f726d47 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2334,8 +2334,10 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, return err; err = sock_error(sock->sk); - if (err) + if (err) { + datagrams = err; goto out_put; + } entry = mmsg; compat_entry = (struct compat_mmsghdr __user *)mmsg; -- 2.12.0