From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 26 Feb 2018 21:27:38 +0100 (CET) Received: from mail.linuxfoundation.org ([140.211.169.12]:51280 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23990723AbeBZU1a6nK4x (ORCPT ); Mon, 26 Feb 2018 21:27:30 +0100 Received: from localhost (clnet-b04-243.ikbnet.co.at [83.175.124.243]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 54F62E4B; Mon, 26 Feb 2018 20:27:24 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Mamonov , James Hogan , Ralf Baechle , Al Viro , linux-mips@linux-mips.org Subject: [PATCH 4.15 07/64] MIPS: Drop spurious __unused in struct compat_flock Date: Mon, 26 Feb 2018 21:21:44 +0100 Message-Id: <20180226202153.748429368@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180226202153.453363333@linuxfoundation.org> References: <20180226202153.453363333@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 62722 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Hogan commit 6ae1756faddefd7494353380ee546dd38c2f97eb upstream. MIPS' struct compat_flock doesn't match the 32-bit struct flock, as it has an extra short __unused before pad[4], which combined with alignment increases the size to 40 bytes compared with struct flock's 36 bytes. Since commit 8c6657cb50cb ("Switch flock copyin/copyout primitives to copy_{from,to}_user()"), put_compat_flock() writes the full compat_flock struct to userland, which results in corruption of the userland word after the struct flock when running 32-bit userlands on 64-bit kernels. This was observed to cause a bus error exception when starting Firefox on Debian 8 (Jessie). Reported-by: Peter Mamonov Signed-off-by: James Hogan Tested-by: Peter Mamonov Cc: Ralf Baechle Cc: Al Viro Cc: linux-mips@linux-mips.org Cc: # 4.13+ Patchwork: https://patchwork.linux-mips.org/patch/18646/ Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/compat.h | 1 - 1 file changed, 1 deletion(-) --- a/arch/mips/include/asm/compat.h +++ b/arch/mips/include/asm/compat.h @@ -86,7 +86,6 @@ struct compat_flock { compat_off_t l_len; s32 l_sysid; compat_pid_t l_pid; - short __unused; s32 pad[4]; };