From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754949AbZIOT33 (ORCPT ); Tue, 15 Sep 2009 15:29:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752851AbZIOT32 (ORCPT ); Tue, 15 Sep 2009 15:29:28 -0400 Received: from brick.kernel.dk ([93.163.65.50]:51386 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752019AbZIOT31 (ORCPT ); Tue, 15 Sep 2009 15:29:27 -0400 Date: Tue, 15 Sep 2009 21:29:30 +0200 From: Jens Axboe To: npiggin@suse.de Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [patch 5/5] fs: fix bdi writeback use after free 2 Message-ID: <20090915192930.GQ23126@kernel.dk> References: <20090915191903.290006007@suse.de> <20090915192243.247202587@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090915192243.247202587@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 16 2009, npiggin@suse.de wrote: > work can be gone after wb_clear_pending, so load the sb from it first. This one is already moot, I fixed that in an earlier patch. > > Signed-off-by: Nick Piggin > --- > fs/fs-writeback.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > Index: linux-2.6/fs/fs-writeback.c > =================================================================== > --- linux-2.6.orig/fs/fs-writeback.c > +++ linux-2.6/fs/fs-writeback.c > @@ -783,6 +783,7 @@ long wb_do_writeback(struct bdi_writebac > > while ((work = get_next_work_item(bdi, wb)) != NULL) { > enum writeback_sync_modes sync_mode; > + struct super_block *sb; > > nr_pages = work->nr_pages; > > @@ -794,6 +795,8 @@ long wb_do_writeback(struct bdi_writebac > else > sync_mode = work->sync_mode; > > + sb = work->sb; > + > /* > * If this isn't a data integrity operation, just notify > * that we have seen this work and we are now starting it. > @@ -801,7 +804,7 @@ long wb_do_writeback(struct bdi_writebac > if (sync_mode == WB_SYNC_NONE) > wb_clear_pending(wb, work); > > - wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0); > + wrote += wb_writeback(wb, nr_pages, sb, sync_mode, 0); > > /* > * This is a data integrity writeback, so only do the > > -- Jens Axboe