Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757086AbXJCIHA (ORCPT ); Wed, 3 Oct 2007 04:07:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753210AbXJCIG2 (ORCPT ); Wed, 3 Oct 2007 04:06:28 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:34929 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752672AbXJCIGZ (ORCPT ); Wed, 3 Oct 2007 04:06:25 -0400 Message-ID: <47034D80.2080408@cn.fujitsu.com> Date: Wed, 03 Oct 2007 17:06:24 +0900 From: Shi Weihua User-Agent: Thunderbird 2.0.0.5 (Windows/20070716) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: [PATCH 1/3] signal(i386): 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: 1559 Lines: 43 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 i386,version is 2.6.23-rc8. Signed-off-by: Shi Weihua diff -pur linux-2.6.23-rc8.orig/arch/i386/kernel/signal.c linux-2.6.23-rc8/arch/i386/kernel/signal.c --- linux-2.6.23-rc8.orig/arch/i386/kernel/signal.c 2007-09-26 09:44:08.000000000 +0900 +++ linux-2.6.23-rc8/arch/i386/kernel/signal.c 2007-09-26 13:14:25.000000000 +0900 @@ -332,6 +332,10 @@ static int setup_frame(int sig, struct k frame = get_sigframe(ka, regs, sizeof(*frame)); + if ((ka->sa.sa_flags & SA_ONSTACK) && + !sas_ss_flags((unsigned long)frame)) + goto give_sigsegv; + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; @@ -425,6 +429,10 @@ static int setup_rt_frame(int sig, struc frame = get_sigframe(ka, regs, sizeof(*frame)); + if ((ka->sa.sa_flags & SA_ONSTACK) && + !sas_ss_flags((unsigned long)frame)) + 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/