From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754748Ab3CRUG6 (ORCPT ); Mon, 18 Mar 2013 16:06:58 -0400 Received: from terminus.zytor.com ([198.137.202.10]:38983 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753461Ab3CRUG4 (ORCPT ); Mon, 18 Mar 2013 16:06:56 -0400 Date: Mon, 18 Mar 2013 13:05:25 -0700 From: tip-bot for CQ Tang Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, cq.tang@intel.com, stable@vger.kernel.org, tglx@linutronix.de, mike.marciniszyn@intel.com, hpa@linux.intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, cq.tang@intel.com, stable@vger.kernel.org, tglx@linutronix.de, mike.marciniszyn@intel.com, hpa@linux.intel.com In-Reply-To: <20130318150221.8439.993.stgit@phlsvslse11.ph.intel.com> References: <20130318150221.8439.993.stgit@phlsvslse11.ph.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86-64: Fix the failure case in copy_user_handle_tail() Git-Commit-ID: 66db3feb486c01349f767b98ebb10b0c3d2d021b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Mon, 18 Mar 2013 13:05:30 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 66db3feb486c01349f767b98ebb10b0c3d2d021b Gitweb: http://git.kernel.org/tip/66db3feb486c01349f767b98ebb10b0c3d2d021b Author: CQ Tang AuthorDate: Mon, 18 Mar 2013 11:02:21 -0400 Committer: H. Peter Anvin CommitDate: Mon, 18 Mar 2013 11:32:03 -0700 x86-64: Fix the failure case in copy_user_handle_tail() The increment of "to" in copy_user_handle_tail() will have incremented before a failure has been noted. This causes us to skip a byte in the failure case. Only do the increment when assured there is no failure. Signed-off-by: CQ Tang Link: http://lkml.kernel.org/r/20130318150221.8439.993.stgit@phlsvslse11.ph.intel.com Signed-off-by: Mike Marciniszyn Signed-off-by: H. Peter Anvin Cc: --- arch/x86/lib/usercopy_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 05928aa..906fea3 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -74,10 +74,10 @@ copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest) char c; unsigned zero_len; - for (; len; --len) { + for (; len; --len, to++) { if (__get_user_nocheck(c, from++, sizeof(char))) break; - if (__put_user_nocheck(c, to++, sizeof(char))) + if (__put_user_nocheck(c, to, sizeof(char))) break; }