From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <51B1A7F0.8010406@redhat.com> Date: Fri, 07 Jun 2013 11:29:20 +0200 From: Jerome Marchand MIME-Version: 1.0 To: Jiang Liu CC: Greg Kroah-Hartman , Nitin Gupta , Minchan Kim , Jiang Liu , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3 01/10] zram: avoid invalid memory access in zram_exit() References: <1370534851-26056-1-git-send-email-jiang.liu@huawei.com> <1370534851-26056-2-git-send-email-jiang.liu@huawei.com> In-Reply-To: <1370534851-26056-2-git-send-email-jiang.liu@huawei.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 06/06/2013 06:07 PM, Jiang Liu wrote: > Memory for zram->disk object may have already been freed after returning > from destroy_device(zram), then it's unsafe for zram_reset_device(zram) > to access zram->disk again. > > We can't solve this bug by flipping the order of destroy_device(zram) > and zram_reset_device(zram), that will cause deadlock issues to the > zram sysfs handler. > > So fix it by holding an extra reference to zram->disk before calling > destroy_device(zram). > > Signed-off-by: Jiang Liu > Cc: stable@vger.kernel.org Acked-by: Jerome Marchand