Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759552AbcCVLOu (ORCPT ); Tue, 22 Mar 2016 07:14:50 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56565 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758729AbcCVKmG (ORCPT ); Tue, 22 Mar 2016 06:42:06 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Al Viro , Luis Henriques Subject: [PATCH 3.16.y-ckt 048/142] do_last(): don't let a bogus return value from ->open() et.al. to confuse us Date: Tue, 22 Mar 2016 10:39:37 +0000 Message-Id: <1458643271-4227-49-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> References: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1063 Lines: 35 3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Al Viro commit c80567c82ae4814a41287618e315a60ecf513be6 upstream. ... into returning a positive to path_openat(), which would interpret that as "symlink had been encountered" and proceed to corrupt memory, etc. It can only happen due to a bug in some ->open() instance or in some LSM hook, etc., so we report any such event *and* make sure it doesn't trick us into further unpleasantness. Signed-off-by: Al Viro Signed-off-by: Luis Henriques --- fs/namei.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/namei.c b/fs/namei.c index 8a0c3d9d8298..34f8224be4ed 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3108,6 +3108,10 @@ opened: goto exit_fput; } out: + if (unlikely(error > 0)) { + WARN_ON(1); + error = -EINVAL; + } if (got_write) mnt_drop_write(nd->path.mnt); path_put(&save_parent);