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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EA2D0C433FE for ; Mon, 21 Nov 2022 20:07:16 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1oxD4V-0004gZ-42; Mon, 21 Nov 2022 20:07:15 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oxD4R-0004gS-9z for linux-f2fs-devel@lists.sourceforge.net; Mon, 21 Nov 2022 20:07:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:Mime-Version :References:In-Reply-To:Message-Id:Subject:Cc:To:From:Date:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=uZReaScaLIpKyiz5HiuhJzPI9e/ZmSUHTeBduh0wRKU=; b=Q+RImqrm8LWHjkCatLT1Bp24tT 3E0hb4bwHgC5th7xuKQE886mYMPY8qCCkprX8bejEpu+TRuvp7gp2mG8txw9kQy5Bs5S1XjpWoaaW VdWg5xLDzsF/WexEsxjA+GVjjxD0a3Ia4974lqNh4ZSy5qoD+ejhMusUTsPmxsUjZSYo=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:Mime-Version:References: In-Reply-To:Message-Id:Subject:Cc:To:From:Date:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=uZReaScaLIpKyiz5HiuhJzPI9e/ZmSUHTeBduh0wRKU=; b=MAiDdREybeJplY4oT66rx0H/ak YGJx1cwr3mzXm3FOojqQ3ehZtbjAyatHJXCl4Pf1LRKlhGBwDlc71UMIvH61rTk/In906QzrQjjLJ Jz6/+rjEZfqH8sCoZ3HkufVpYYQYkChiinGuGZZ+YOhjNPiT+/6RR/SCy++cfmfqv5HU=; Received: from ams.source.kernel.org ([145.40.68.75]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1oxD4J-0001Nj-9y for linux-f2fs-devel@lists.sourceforge.net; Mon, 21 Nov 2022 20:07:10 +0000 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 ams.source.kernel.org (Postfix) with ESMTPS id E0503B815D5; Mon, 21 Nov 2022 19:48:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35382C433C1; Mon, 21 Nov 2022 19:48:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1669060121; bh=uPYHTP2Ipj1sjrcHIm6CYiJh1FA0Hkn6zRTUosyzZhU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TrV/2DjxF1rutFbntPYYC9ONN0Uda6FFTBfJlApXphenB+VGOZ5iLxlUIkzmv7s7E lZr0pL2iT2j274d6+x2nxXaHGy3/wnUtCl/KUrmLKCxa2ewYEAXooKMndVypDUcvl2 63Fx/Kosh/hLvBUeAm4T/PKzCJLBd/aiTg8bd+CI= Date: Mon, 21 Nov 2022 11:48:40 -0800 From: Andrew Morton To: Alexander Potapenko Message-Id: <20221121114840.c407626c13706ff993efabe3@linux-foundation.org> In-Reply-To: <20221121112134.407362-1-glider@google.com> References: <20221121112134.407362-1-glider@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 X-Headers-End: 1oxD4J-0001Nj-9y Subject: Re: [f2fs-dev] [PATCH 1/5] fs: ext4: initialize fsdata in pagecache_write() X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tytso@mit.edu, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, Eric Biggers , adilger.kernel@dilger.ca, linux-fsdevel@vger.kernel.org, jaegeuk@kernel.org, linux-ext4@vger.kernel.org, syzbot+9767be679ef5016b6082@syzkaller.appspotmail.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On Mon, 21 Nov 2022 12:21:30 +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. > > ... > I'm assuming that this is not-a-bug, and that these changes are purely workarounds for a KMSAN shortcoming? If true, this important info should be included in each changelog, please. If false, please provide a full description of the end-user visible effects of the bug. Also, it would be helpful to describe why it is not considered practical to teach KMSAN to handle this? > --- 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); _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel