From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760307AbYKDXwy (ORCPT ); Tue, 4 Nov 2008 18:52:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757042AbYKDXkS (ORCPT ); Tue, 4 Nov 2008 18:40:18 -0500 Received: from cantor.suse.de ([195.135.220.2]:47732 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756340AbYKDXkQ (ORCPT ); Tue, 4 Nov 2008 18:40:16 -0500 Date: Tue, 4 Nov 2008 15:33:03 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ingo Molnar , David Rientjes Subject: [patch 41/57] x86: avoid dereferencing beyond stack + THREAD_SIZE Message-ID: <20081104233303.GP659@suse.de> References: <20081104232144.186593464@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="x86-avoid-dereferencing-beyond-stack-thread_size.patch" In-Reply-To: <20081104233028.GA659@suse.de> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: David Rientjes commit e1e23bb0513520035ec934fa3483507cb6648b7c upstream x86: avoid dereferencing beyond stack + THREAD_SIZE It's possible for get_wchan() to dereference past task->stack + THREAD_SIZE while iterating through instruction pointers if fp equals the upper boundary, causing a kernel panic. Signed-off-by: David Rientjes Signed-off-by: Ingo Molnar Cc: Chuck Ebbert Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/process_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -729,12 +729,12 @@ unsigned long get_wchan(struct task_stru if (!p || p == current || p->state==TASK_RUNNING) return 0; stack = (unsigned long)task_stack_page(p); - if (p->thread.sp < stack || p->thread.sp > stack+THREAD_SIZE) + if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE) return 0; fp = *(u64 *)(p->thread.sp); do { if (fp < (unsigned long)stack || - fp > (unsigned long)stack+THREAD_SIZE) + fp >= (unsigned long)stack+THREAD_SIZE) return 0; ip = *(u64 *)(fp+8); if (!in_sched_functions(ip)) --