From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755661Ab1BYPdP (ORCPT ); Fri, 25 Feb 2011 10:33:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:27419 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754575Ab1BYPdN (ORCPT ); Fri, 25 Feb 2011 10:33:13 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH] afs: Fix oops in afs_unlink_writeback To: torvalds@osdl.org, akpm@linux-foundation.org Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, Anton Blanchard , David Howells Date: Fri, 25 Feb 2011 15:33:02 +0000 Message-ID: <20110225153301.27864.14291.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anton Blanchard I'm seeing the following oops when testing afs: Unable to handle kernel paging request for data at address 0x00000008 ... NIP [c0000000003393b0] .afs_unlink_writeback+0x38/0xc0 LR [c00000000033987c] .afs_put_writeback+0x98/0xec Call Trace: [c00000000345f600] [c00000000033987c] .afs_put_writeback+0x98/0xec [c00000000345f690] [c00000000033ae80] .afs_write_begin+0x6a4/0x75c [c00000000345f790] [c00000000012b77c] .generic_file_buffered_write+0x148/0x320 [c00000000345f8d0] [c00000000012e1b8] .__generic_file_aio_write+0x37c/0x3e4 [c00000000345f9d0] [c00000000012e2a8] .generic_file_aio_write+0x88/0xfc [c00000000345fa90] [c0000000003390a8] .afs_file_write+0x10c/0x178 [c00000000345fb40] [c000000000188788] .do_sync_write+0xc4/0x128 [c00000000345fcc0] [c000000000189658] .vfs_write+0xe8/0x1d8 [c00000000345fd70] [c000000000189884] .SyS_write+0x68/0xb0 [c00000000345fe30] [c000000000008564] syscall_exit+0x0/0x40 afs_write_begin hits an error and calls afs_unlink_writeback. In there we do list_del_init on an uninitialised list. The patch below initialises ->link when creating the afs_writeback struct. Signed-off-by: Anton Blanchard Signed-off-by: David Howells --- fs/afs/write.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/afs/write.c b/fs/afs/write.c index 15690bb..789b3af 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -140,6 +140,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping, candidate->first = candidate->last = index; candidate->offset_first = from; candidate->to_last = to; + INIT_LIST_HEAD(&candidate->link); candidate->usage = 1; candidate->state = AFS_WBACK_PENDING; init_waitqueue_head(&candidate->waitq);