Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965171Ab3CZPXG (ORCPT ); Tue, 26 Mar 2013 11:23:06 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:53890 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965028Ab3CZPW6 (ORCPT ); Tue, 26 Mar 2013 11:22:58 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: CQ Tang , Mike Marciniszyn , "H. Peter Anvin" , Luis Henriques Subject: [PATCH 081/150] x86-64: Fix the failure case in copy_user_handle_tail() Date: Tue, 26 Mar 2013 15:19:40 +0000 Message-Id: <1364311249-14454-82-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1364311249-14454-1-git-send-email-luis.henriques@canonical.com> References: <1364311249-14454-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1587 Lines: 48 3.5.7.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: CQ Tang commit 66db3feb486c01349f767b98ebb10b0c3d2d021b upstream. 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 Signed-off-by: Luis Henriques --- 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 e5b130b..cc9de31 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -72,10 +72,10 @@ 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; } -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/