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 EFB98C04A68 for ; Thu, 28 Jul 2022 06:54:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234282AbiG1Gye (ORCPT ); Thu, 28 Jul 2022 02:54:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233104AbiG1Gyd (ORCPT ); Thu, 28 Jul 2022 02:54:33 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 101145C96F for ; Wed, 27 Jul 2022 23:54:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658991271; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=l+70inD/0eDqE7YP+CInia/k6qJaVaSuXf8b8WY0ijM=; b=Q8gDDiLU9zH5rGiDwq9bqoRGmg95aardaaGse1pL3JNHT4wjA8N8T6fFEwgyZ8mrZGoU89 77DagG/AuSalXh92EgYCKa2YUALOkUPTB2EQcmMN58ZmQ3YucVUmMYOzVotM7W5t/Zw0WV aIV7c1giX/jguoW6/FFKxvodY5PnIuk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-647-A_pNsxNbOJiIM6IwvkWG8Q-1; Thu, 28 Jul 2022 02:54:27 -0400 X-MC-Unique: A_pNsxNbOJiIM6IwvkWG8Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0E60785A584; Thu, 28 Jul 2022 06:54:27 +0000 (UTC) Received: from fedora (unknown [10.40.193.52]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1CE78C28100; Thu, 28 Jul 2022 06:54:25 +0000 (UTC) Date: Thu, 28 Jul 2022 08:54:23 +0200 From: Lukas Czerner To: Jan Kara Cc: Ted Tso , linux-ext4@vger.kernel.org, Tadeusz Struk , syzbot+bd13648a53ed6933ca49@syzkaller.appspotmail.com Subject: Re: [PATCH] ext4: Avoid crash when inline data creation follows DIO write Message-ID: <20220728065423.wzbpa7ce35qxbxet@fedora> References: <20220727155753.13969-1-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220727155753.13969-1-jack@suse.cz> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed, Jul 27, 2022 at 05:57:53PM +0200, Jan Kara wrote: > When inode is created and written to using direct IO, there is nothing > to clear the EXT4_STATE_MAY_INLINE_DATA flag. Thus when inode gets > truncated later to say 1 byte and written using normal write, we will > try to store the data as inline data. This confuses the code later > because the inode now has both normal block and inline data allocated > and the confusion manifests for example as: > > kernel BUG at fs/ext4/inode.c:2721! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 359 Comm: repro Not tainted 5.19.0-rc8-00001-g31ba1e3b8305-dirty #15 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 > RIP: 0010:ext4_writepages+0x363d/0x3660 > RSP: 0018:ffffc90000ccf260 EFLAGS: 00010293 > RAX: ffffffff81e1abcd RBX: 0000008000000000 RCX: ffff88810842a180 > RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000 > RBP: ffffc90000ccf650 R08: ffffffff81e17d58 R09: ffffed10222c680b > R10: dfffe910222c680c R11: 1ffff110222c680a R12: ffff888111634128 > R13: ffffc90000ccf880 R14: 0000008410000000 R15: 0000000000000001 > FS: 00007f72635d2640(0000) GS:ffff88811b000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000565243379180 CR3: 000000010aa74000 CR4: 0000000000150eb0 > Call Trace: > > do_writepages+0x397/0x640 > filemap_fdatawrite_wbc+0x151/0x1b0 > file_write_and_wait_range+0x1c9/0x2b0 > ext4_sync_file+0x19e/0xa00 > vfs_fsync_range+0x17b/0x190 > ext4_buffered_write_iter+0x488/0x530 > ext4_file_write_iter+0x449/0x1b90 > vfs_write+0xbcd/0xf40 > ksys_write+0x198/0x2c0 > __x64_sys_write+0x7b/0x90 > do_syscall_64+0x3d/0x90 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > Fix the problem by clearing EXT4_STATE_MAY_INLINE_DATA when we are doing > direct IO write to a file. Looks good, thanks. Reviewed-by: Lukas Czerner > > Reported-by: Tadeusz Struk > Reported-by: syzbot+bd13648a53ed6933ca49@syzkaller.appspotmail.com > Link: https://syzkaller.appspot.com/bug?id=a1e89d09bbbcbd5c4cb45db230ee28c822953984 > Signed-off-by: Jan Kara > --- > fs/ext4/file.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/fs/ext4/file.c b/fs/ext4/file.c > index 109d07629f81..cab5dfed1cd6 100644 > --- a/fs/ext4/file.c > +++ b/fs/ext4/file.c > @@ -528,6 +528,12 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) > ret = -EAGAIN; > goto out; > } > + /* > + * Make sure inline data cannot be created anymore since we are going > + * to allocate blocks for DIO. We know the inode does not have any > + * inline data now because ext4_dio_supported() checked for that. > + */ > + ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); > > offset = iocb->ki_pos; > count = ret; > -- > 2.35.3 >