Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753785AbaAVEWZ (ORCPT ); Tue, 21 Jan 2014 23:22:25 -0500 Received: from merlin.infradead.org ([205.233.59.134]:45021 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750809AbaAVEWW (ORCPT ); Tue, 21 Jan 2014 23:22:22 -0500 Date: Tue, 21 Jan 2014 20:22:09 -0800 From: Jens Axboe To: Raghavendra K T Cc: Alexander Viro , Matias Bjorling , Andrew Morton , Yuanhan Liu , "Darrick J. Wong" , Jan Kara , Johannes Weiner , Zhang Yanfei , Jeff , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Sumanth Subject: Re: [RFC PATCH V3 1/2] null_blk: Null pointer deference problem in alloc_page_buffers Message-ID: <20140122042209.GF20347@kernel.dk> References: <1390303800-22422-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <1390303800-22422-2-git-send-email-raghavendra.kt@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1390303800-22422-2-git-send-email-raghavendra.kt@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 21 2014, Raghavendra K T wrote: > If we load the null_blk module with bs=8k we get following oops: > [ 3819.812190] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 > [ 3819.812387] IP: [] create_empty_buffers+0x28/0xaf > [ 3819.812527] PGD 219244067 PUD 215a06067 PMD 0 > [ 3819.812640] Oops: 0000 [#1] SMP > [ 3819.812772] Modules linked in: null_blk(+) > > Fix that by resetting block size to PAGE_SIZE if it is greater than PAGE_SIZE Thanks, applied. -- Jens Axboe -- 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/