From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755550AbcHSHXb (ORCPT ); Fri, 19 Aug 2016 03:23:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:49739 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755470AbcHSHMB (ORCPT ); Fri, 19 Aug 2016 03:12:01 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dave Weinstein , Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 057/100] arm: oabi compat: add missing access checks Date: Fri, 19 Aug 2016 09:10:56 +0200 Message-Id: <946e59e2ee61710ef9a549ca22b3e7fc796a011e.1471589700.git.jslaby@suse.cz> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Weinstein 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 7de249964f5578e67b99699c5f0b405738d820a2 upstream. Add access checks to sys_oabi_epoll_wait() and sys_oabi_semtimedop(). This fixes CVE-2016-3857, a local privilege escalation under CONFIG_OABI_COMPAT. Reported-by: Chiachih Wu Reviewed-by: Kees Cook Reviewed-by: Nicolas Pitre Signed-off-by: Dave Weinstein Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby --- arch/arm/kernel/sys_oabi-compat.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c index 3e94811690ce..a0aee80b608d 100644 --- a/arch/arm/kernel/sys_oabi-compat.c +++ b/arch/arm/kernel/sys_oabi-compat.c @@ -275,8 +275,12 @@ asmlinkage long sys_oabi_epoll_wait(int epfd, mm_segment_t fs; long ret, err, i; - if (maxevents <= 0 || maxevents > (INT_MAX/sizeof(struct epoll_event))) + if (maxevents <= 0 || + maxevents > (INT_MAX/sizeof(*kbuf)) || + maxevents > (INT_MAX/sizeof(*events))) return -EINVAL; + if (!access_ok(VERIFY_WRITE, events, sizeof(*events) * maxevents)) + return -EFAULT; kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL); if (!kbuf) return -ENOMEM; @@ -313,6 +317,8 @@ asmlinkage long sys_oabi_semtimedop(int semid, if (nsops < 1 || nsops > SEMOPM) return -EINVAL; + if (!access_ok(VERIFY_READ, tsops, sizeof(*tsops) * nsops)) + return -EFAULT; sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL); if (!sops) return -ENOMEM; -- 2.9.3