From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id D1E646B0078 for ; Thu, 9 Jun 2011 06:20:47 -0400 (EDT) Received: by fxm18 with SMTP id 18so1237544fxm.14 for ; Thu, 09 Jun 2011 03:20:42 -0700 (PDT) Date: Thu, 9 Jun 2011 12:20:38 +0200 From: Tejun Heo Subject: Re: [PATCH] mm: dmapool: fix possible use after free in dmam_pool_destroy() Message-ID: <20110609102038.GE11773@htj.dyndns.org> References: <20110602142242.GA4115@maxin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110602142242.GA4115@maxin> Sender: owner-linux-mm@kvack.org List-ID: To: Maxin B John Cc: eike-kernel@sf-tec.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dima@android.com, willy@linux.intel.com, segooon@gmail.com, jkosina@suse.cz, tglx@linutronix.de Hello, On Thu, Jun 02, 2011 at 05:22:42PM +0300, Maxin B John wrote: > > The pool itself is not used there, only the address where the pool > > has been.This will only lead to any trouble if something else is allocated to > > the same place and inserted into the devres list of the same device between > > the dma_pool_destroy() and devres_destroy(). Which can't happen. devres release is bound to device driver model and a device can't be re-attached before release is complete. ie. those operations are serialized, so the failure mode is only theoretical. > Thank you very much for explaining it in detail. > > > But I agree that this is bad style. But if you are going to change > > this please also have a look at devm_iounmap() in lib/devres.c. Maybe also the > > devm_*irq* functions need the same changes. > > As per your suggestion, I have made similar modifications for lib/devres.c and > kernel/irq/devres.c > > CCed the maintainers of the respective files. > > Signed-off-by: Maxin B. John But it shouldn't hurt and if it helps memleak. Acked-by: Tejun Heo Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org