From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751625AbeEFKwx (ORCPT ); Sun, 6 May 2018 06:52:53 -0400 Received: from terminus.zytor.com ([198.137.202.136]:38873 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbeEFKwv (ORCPT ); Sun, 6 May 2018 06:52:51 -0400 Date: Sun, 6 May 2018 03:52:35 -0700 From: "tip-bot for Luck, Tony" Message-ID: Cc: dvyukov@google.com, tony.luck@intel.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com, bp@suse.de, linux-edac@vger.kernel.org Reply-To: tony.luck@intel.com, dvyukov@google.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, bp@suse.de, hpa@zytor.com, mingo@kernel.org In-Reply-To: <20180427163707.ktaiysvbk3yhk4wm@agluck-desk> References: <20180427163707.ktaiysvbk3yhk4wm@agluck-desk> To: linux-tip-commits@vger.kernel.org Subject: [tip:ras/core] x86/MCE: Fix stack out-of-bounds write in mce-inject.c: Flags_read() Git-Commit-ID: 985c78d3ff8e9c74450fa2bb08eb55e680d999ca 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 985c78d3ff8e9c74450fa2bb08eb55e680d999ca Gitweb: https://git.kernel.org/tip/985c78d3ff8e9c74450fa2bb08eb55e680d999ca Author: Luck, Tony AuthorDate: Fri, 27 Apr 2018 09:37:08 -0700 Committer: Thomas Gleixner CommitDate: Sun, 6 May 2018 12:46:39 +0200 x86/MCE: Fix stack out-of-bounds write in mce-inject.c: Flags_read() Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE] in flags_read() is two characters long. But the sprintf() adds a trailing newline and will add a terminating NUL byte. So MAX_FLAG_OPT_SIZE needs to be 4. sprintf() calls vsnprintf() and *that* does return: " * The return value is the number of characters which would * be generated for the given input, excluding the trailing * '\0', as per ISO C99." Note the "excluding". Reported-by: Dmitry Vyukov Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Cc: linux-edac Link: http://lkml.kernel.org/r/20180427163707.ktaiysvbk3yhk4wm@agluck-desk --- arch/x86/kernel/cpu/mcheck/mce-inject.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c index 475cb4f5f14f..c805a06e14c3 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-inject.c +++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c @@ -48,7 +48,7 @@ static struct dentry *dfs_inj; static u8 n_banks; -#define MAX_FLAG_OPT_SIZE 3 +#define MAX_FLAG_OPT_SIZE 4 #define NBCFG 0x44 enum injection_type {