From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934321AbcKNCYm (ORCPT ); Sun, 13 Nov 2016 21:24:42 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:47094 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934128AbcKNCYf (ORCPT ); Sun, 13 Nov 2016 21:24:35 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Al Viro" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 276/346] ia64: copy_from_user() should zero the destination on access_ok() failure In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro commit a5e541f796f17228793694d64b507f5f57db4cd7 upstream. Signed-off-by: Al Viro [bwh: Backported to 3.16: no calls to check_object_size()] Signed-off-by: Ben Hutchings --- --- a/arch/ia64/include/asm/uaccess.h +++ b/arch/ia64/include/asm/uaccess.h @@ -262,17 +262,15 @@ __copy_from_user (void *to, const void _ __cu_len; \ }) -#define copy_from_user(to, from, n) \ -({ \ - void *__cu_to = (to); \ - const void __user *__cu_from = (from); \ - long __cu_len = (n); \ - \ - __chk_user_ptr(__cu_from); \ - if (__access_ok(__cu_from, __cu_len, get_fs())) \ - __cu_len = __copy_user((__force void __user *) __cu_to, __cu_from, __cu_len); \ - __cu_len; \ -}) +static inline unsigned long +copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (likely(__access_ok(from, n, get_fs()))) + n = __copy_user((__force void __user *) to, from, n); + else + memset(to, 0, n); + return n; +} #define __copy_in_user(to, from, size) __copy_user((to), (from), (size))