From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933112AbcCGXWF (ORCPT ); Mon, 7 Mar 2016 18:22:05 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:39604 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753966AbcCGWzX (ORCPT ); Mon, 7 Mar 2016 17:55:23 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Al Viro , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 215/273] do_last(): don't let a bogus return value from ->open() et.al. to confuse us Date: Mon, 7 Mar 2016 14:50:06 -0800 Message-Id: <1457391064-6660-216-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457391064-6660-1-git-send-email-kamal@canonical.com> References: <1457391064-6660-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt5 -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: Kamal Mostafa --- fs/namei.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/namei.c b/fs/namei.c index f39a798..3500b12 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3213,6 +3213,10 @@ 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); -- 2.7.0