Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765233AbXKOLcl (ORCPT ); Thu, 15 Nov 2007 06:32:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757336AbXKOLcd (ORCPT ); Thu, 15 Nov 2007 06:32:33 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:37299 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759167AbXKOLcc (ORCPT ); Thu, 15 Nov 2007 06:32:32 -0500 Date: Thu, 15 Nov 2007 12:32:04 +0100 From: Ingo Molnar To: Nick Piggin Cc: David Miller , mpm@selenic.com, rjw@sisk.pl, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, Thomas Gleixner Subject: [patch] slob: fix memory corruption Message-ID: <20071115113204.GA24463@elte.hu> References: <20071114225335.GV19691@waste.org> <20071114.154143.112110604.davem@davemloft.net> <20071115104331.GA11390@elte.hu> <200711152157.59409.nickpiggin@yahoo.com.au> <20071115112820.GA18228@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071115112820.GA18228@elte.hu> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1805 Lines: 55 * Ingo Molnar wrote: > > I had implemented SLOB in userspace, so I resynched and think I > > found your problem. Sorry for the attachment format -- this mailer > > isn't the best. I'm really computer illiterate when it comes to > > userspace... > > thx, i'll try your fix in a minute. that did the trick! Nick, find an updated patch below. (reference to the bugzilla added.) Ingo --------------------> Subject: slob: fix memory corruption From: Nick Piggin Previously, it would be possible for prev->next to point to &free_slob_pages, and thus we would try to move a list onto itself, and bad things would happen. It seems a bit hairy to be doing list operations with the list marker as an entry, rather than a head, but... this resolves the following crash: http://bugzilla.kernel.org/show_bug.cgi?id=9379 Signed-off-by: Nick Piggin Signed-off-by: Ingo Molnar --- mm/slob.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Index: linux/mm/slob.c =================================================================== --- linux.orig/mm/slob.c +++ linux/mm/slob.c @@ -321,7 +321,8 @@ static void *slob_alloc(size_t size, gfp /* Improve fragment distribution and reduce our average * search time by starting our next search here. (see * Knuth vol 1, sec 2.5, pg 449) */ - if (free_slob_pages.next != prev->next) + if (prev != free_slob_pages.prev && + free_slob_pages.next != prev->next) list_move_tail(&free_slob_pages, prev->next); break; } - 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/