From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f46.google.com (mail-la0-f46.google.com [209.85.215.46]) by kanga.kvack.org (Postfix) with ESMTP id 3A7146B0038 for ; Mon, 7 Sep 2015 12:40:02 -0400 (EDT) Received: by lagj9 with SMTP id j9so55337264lag.2 for ; Mon, 07 Sep 2015 09:40:01 -0700 (PDT) Received: from mail-lb0-x22b.google.com (mail-lb0-x22b.google.com. [2a00:1450:4010:c04::22b]) by mx.google.com with ESMTPS id x3si434926lax.158.2015.09.07.09.40.00 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Sep 2015 09:40:00 -0700 (PDT) Received: by lbbmp1 with SMTP id mp1so41664603lbb.1 for ; Mon, 07 Sep 2015 09:39:59 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20150902194019.GL22326@mtj.duckdns.org> Date: Mon, 7 Sep 2015 18:39:59 +0200 Message-ID: Subject: Fwd: Use-after-free in page_cache_async_readahead From: Andrey Konovalov Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Jens Axboe , Jan Kara , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dmitry Vyukov , Alexander Potapenko , Kostya Serebryany On Thu, Sep 3, 2015 at 1:49 PM, Andrey Konovalov wrote: > On Wed, Sep 2, 2015 at 9:40 PM, Tejun Heo wrote: >> Hello, Andrey. > > Hello Tejun, > >> On Wed, Sep 02, 2015 at 01:08:52PM +0200, Andrey Konovalov wrote: >>> While running KASAN on 4.2 with Trinity I got the following report: >>> >>> ================================================================== >>> BUG: KASan: use after free in page_cache_async_readahead+0x2cb/0x3f0 >>> at addr ffff880034bf6690 >>> Read of size 8 by task sshd/2571 >>> ============================================================================= >>> BUG kmalloc-16 (Tainted: G W ): kasan: bad access detected >>> ----------------------------------------------------------------------------- >>> >>> Disabling lock debugging due to kernel taint >>> INFO: Allocated in bdi_init+0x168/0x960 age=554826 cpu=0 pid=6 >> >> Can you please verify that the following patch fixes the issue? > > I've hit this bug only twice during 24 hours of fuzzing, so there's no > fast way to verify this. > I'll be testing with your patch now, and I'll let you know if I hit > the bug again. Hello Tejun, I haven't seen any reports while testing with your patch for the last few days, so I think it's safe to say that your patch fixes the issue. Thanks! > > Thanks! -- 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/ . Don't email: email@kvack.org