Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757579AbXJCIHu (ORCPT ); Wed, 3 Oct 2007 04:07:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753500AbXJCIGh (ORCPT ); Wed, 3 Oct 2007 04:06:37 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:35417 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754565AbXJCIGe (ORCPT ); Wed, 3 Oct 2007 04:06:34 -0400 Message-ID: <47034D84.8050505@cn.fujitsu.com> Date: Wed, 03 Oct 2007 17:06:28 +0900 From: Shi Weihua User-Agent: Thunderbird 2.0.0.5 (Windows/20070716) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Cc: ak@suse.de, discuss@x86-64.org Subject: [PATCH 3/3] signal(x86-64): alternative signal stack wraparound occurs Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2204 Lines: 58 Fixing alternative signal stack wraparound. If a process uses alternative signal stack by using sigaltstack() and that stack overflow, stack wraparound occurs. This patch checks whether the signal frame is on the alternative stack. If the frame is not on there, kill a signal SIGSEGV to the process forcedly then the process will be terminated. This patch is for x86-64,version is 2.6.23-rc8. Signed-off-by: Shi Weihua diff -pur linux-2.6.23-rc8.orig/arch/x86_64/ia32/ia32_signal.c linux-2.6.23-rc8/arch/x86_64/ia32/ia32_signal.c --- linux-2.6.23-rc8.orig/arch/x86_64/ia32/ia32_signal.c 2007-07-09 08:32:17.000000000 +0900 +++ linux-2.6.23-rc8/arch/x86_64/ia32/ia32_signal.c 2007-09-26 12:09:07.000000000 +0900 @@ -428,6 +428,10 @@ int ia32_setup_frame(int sig, struct k_s frame = get_sigframe(ka, regs, sizeof(*frame)); + if ((ka->sa.sa_flags & SA_ONSTACK) + && (sas_ss_flags((unsigned long) frame) == 0)) + goto give_sigsegv; + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; @@ -518,6 +522,10 @@ int ia32_setup_rt_frame(int sig, struct frame = get_sigframe(ka, regs, sizeof(*frame)); + if ((ka->sa.sa_flags & SA_ONSTACK) + && (sas_ss_flags((unsigned long) frame) == 0)) + goto give_sigsegv; + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; diff -pur linux-2.6.23-rc8.orig/arch/x86_64/kernel/signal.c linux-2.6.23-rc8/arch/x86_64/kernel/signal.c --- linux-2.6.23-rc8.orig/arch/x86_64/kernel/signal.c 2007-09-26 09:44:09.000000000 +0900 +++ linux-2.6.23-rc8/arch/x86_64/kernel/signal.c 2007-09-26 12:09:31.000000000 +0900 @@ -235,6 +235,10 @@ static int setup_rt_frame(int sig, struc } else frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8; + if ((ka->sa.sa_flags & SA_ONSTACK) + && (sas_ss_flags((unsigned long) frame) == 0)) + goto give_sigsegv; + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; - 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/