From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756514AbZBJTFt (ORCPT ); Tue, 10 Feb 2009 14:05:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754727AbZBJTDb (ORCPT ); Tue, 10 Feb 2009 14:03:31 -0500 Received: from kroah.org ([198.145.64.141]:53636 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754619AbZBJTDa (ORCPT ); Tue, 10 Feb 2009 14:03:30 -0500 Date: Tue, 10 Feb 2009 10:59:52 -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, Masami Hiramatsu Subject: [patch 06/53] prevent kprobes from catching spurious page faults Message-ID: <20090210185952.GG14308@kroah.com> References: <20090210185337.000769713@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="prevent-kprobes-from-catching-spurious-page-faults.patch" In-Reply-To: <20090210185924.GA14308@kroah.com> 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 2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: Masami Hiramatsu commit 9be260a646bf76fa418ee519afa10196b3164681 upstream. Prevent kprobes from catching spurious faults which will cause infinite recursive page-fault and memory corruption by stack overflow. Signed-off-by: Masami Hiramatsu Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/fault.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -601,8 +601,6 @@ void __kprobes do_page_fault(struct pt_r si_code = SEGV_MAPERR; - if (notify_page_fault(regs)) - return; if (unlikely(kmmio_fault(regs, address))) return; @@ -632,6 +630,9 @@ void __kprobes do_page_fault(struct pt_r if (spurious_fault(address, error_code)) return; + /* kprobes don't want to hook the spurious faults. */ + if (notify_page_fault(regs)) + return; /* * Don't take the mm semaphore here. If we fixup a prefetch * fault we could otherwise deadlock. @@ -639,6 +640,9 @@ void __kprobes do_page_fault(struct pt_r goto bad_area_nosemaphore; } + /* kprobes don't want to hook the spurious faults. */ + if (notify_page_fault(regs)) + return; /* * It's safe to allow irq's after cr2 has been saved and the