From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29D31C43219 for ; Mon, 21 Nov 2022 19:52:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231678AbiKUTw1 (ORCPT ); Mon, 21 Nov 2022 14:52:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229627AbiKUTwY (ORCPT ); Mon, 21 Nov 2022 14:52:24 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66504D39DC; Mon, 21 Nov 2022 11:52:24 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0A5F261457; Mon, 21 Nov 2022 19:52:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3593CC433C1; Mon, 21 Nov 2022 19:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669060343; bh=e3ckNQ3AIoADAgf/ebPYYoIm7JZ0SGqlrtn9J2k3xWQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WVT4pmRQyclkI9wj3E0sS0TMkksmSbkkQqj66ikyHbwPoFKShZspYh3gjOUXrIVkZ 2T5hY3fRA2FrEdkg5Ba9oeUbylKKPFeBQ1mEnh/tk+MakYyUC0d0Sjq3QFOxKqWkQh doaNEiGEUMTR6OB0HxAMCDlO5kUfhujQQm4S1iPL2uCP+7bQYd+u0LrEvpwjEczRce dIKCxAmWSSxBdveRpnjHXK3wETuCajOfXlb4dOnLstiCoubTitlxPk9l8ua8cSGc7W Jt+Tef4yqhp/ZdE19AYHBXoUsqKX7RhRiZTmrHrDSahzG7jiS3ElENnng4xtP3Lop7 Bzd4v4Db3luag== Date: Mon, 21 Nov 2022 19:52:21 +0000 From: Eric Biggers To: Alexander Potapenko Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, tytso@mit.edu, adilger.kernel@dilger.ca, jaegeuk@kernel.org, chao@kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, syzbot+9767be679ef5016b6082@syzkaller.appspotmail.com Subject: Re: [PATCH 1/5] fs: ext4: initialize fsdata in pagecache_write() Message-ID: References: <20221121112134.407362-1-glider@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221121112134.407362-1-glider@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Nov 21, 2022 at 12:21:30PM +0100, Alexander Potapenko wrote: > When aops->write_begin() does not initialize fsdata, KMSAN reports > an error passing the latter to aops->write_end(). > > Fix this by unconditionally initializing fsdata. > > Cc: Eric Biggers > Fixes: c93d8f885809 ("ext4: add basic fs-verity support") > Reported-by: syzbot+9767be679ef5016b6082@syzkaller.appspotmail.com > Signed-off-by: Alexander Potapenko > --- > fs/ext4/verity.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c > index 3c640bd7ecaeb..30e3b65798b50 100644 > --- a/fs/ext4/verity.c > +++ b/fs/ext4/verity.c > @@ -79,7 +79,7 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count, > size_t n = min_t(size_t, count, > PAGE_SIZE - offset_in_page(pos)); > struct page *page; > - void *fsdata; > + void *fsdata = NULL; > int res; > > res = aops->write_begin(NULL, mapping, pos, n, &page, &fsdata); Reviewed-by: Eric Biggers - Eric