From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755739Ab2IIXP6 (ORCPT ); Sun, 9 Sep 2012 19:15:58 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51043 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755469Ab2IIXPt (ORCPT ); Sun, 9 Sep 2012 19:15:49 -0400 Message-Id: <20120909224155.118631523@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 09 Sep 2012 23:42:21 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Miklos Szeredi , "Richard W.M. Jones" Subject: [ 31/95] vfs: canonicalize create mode in build_open_flags() In-Reply-To: <20120909224150.641491654@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi commit e68726ff72cf7ba5e7d789857fcd9a75ca573f03 upstream. Userspace can pass weird create mode in open(2) that we canonicalize to "(mode & S_IALLUGO) | S_IFREG" in vfs_create(). The problem is that we use the uncanonicalized mode before calling vfs_create() with unforseen consequences. So do the canonicalization early in build_open_flags(). Signed-off-by: Miklos Szeredi Tested-by: Richard W.M. Jones Signed-off-by: Ben Hutchings --- fs/open.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/open.c b/fs/open.c index bc132e1..e1f2cdb 100644 --- a/fs/open.c +++ b/fs/open.c @@ -852,9 +852,10 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o int lookup_flags = 0; int acc_mode; - if (!(flags & O_CREAT)) - mode = 0; - op->mode = mode; + if (flags & O_CREAT) + op->mode = (mode & S_IALLUGO) | S_IFREG; + else + op->mode = 0; /* Must never be set by userspace */ flags &= ~FMODE_NONOTIFY;