From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756087Ab2IIX2e (ORCPT ); Sun, 9 Sep 2012 19:28:34 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51280 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756036Ab2IIXQc (ORCPT ); Sun, 9 Sep 2012 19:16:32 -0400 Message-Id: <20120909224159.613727579@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 09 Sep 2012 23:42:55 +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, Al Viro , Al Viro Subject: [ 65/95] vfs: missed source of ->f_pos races 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: Al Viro commit 0e665d5d1125f9f4ccff56a75e814f10f88861a2 upstream. compat_sys_{read,write}v() need the same "pass a copy of file->f_pos" thing as sys_{read,write}{,v}(). Signed-off-by: Al Viro Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- fs/compat.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/compat.c b/fs/compat.c index 6161255..1bdb350 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1155,11 +1155,14 @@ compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, struct file *file; int fput_needed; ssize_t ret; + loff_t pos; file = fget_light(fd, &fput_needed); if (!file) return -EBADF; - ret = compat_readv(file, vec, vlen, &file->f_pos); + pos = file->f_pos; + ret = compat_readv(file, vec, vlen, &pos); + file->f_pos = pos; fput_light(file, fput_needed); return ret; } @@ -1221,11 +1224,14 @@ compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, struct file *file; int fput_needed; ssize_t ret; + loff_t pos; file = fget_light(fd, &fput_needed); if (!file) return -EBADF; - ret = compat_writev(file, vec, vlen, &file->f_pos); + pos = file->f_pos; + ret = compat_writev(file, vec, vlen, &pos); + file->f_pos = pos; fput_light(file, fput_needed); return ret; }