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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79E4CC43460 for ; Mon, 12 Apr 2021 11:30:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 482A261206 for ; Mon, 12 Apr 2021 11:30:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240434AbhDLLbM (ORCPT ); Mon, 12 Apr 2021 07:31:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240413AbhDLLbL (ORCPT ); Mon, 12 Apr 2021 07:31:11 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C456C06138C; Mon, 12 Apr 2021 04:30:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=kWQ0c8ucYe9UV0ATqeFAnzRMY2iAE51PlhKV5u1lmgA=; b=cUlG6NlYie3LJa9ROPnR/w8KN2 JCdeSfOVfIeml1p84gNnsCv7tp+9EaP/qi6AjJ9B9nZGmaLGGKWPjHTdIvaWcevxZqaAkVyH2zIYp YpK1Vp4IdlP++IDrzLyQJenh0Z9PQiQc5EmbthkHVGgJYwguPfIaBbOh+NnGPEke9NwJew87h0P4l V7bgqTmOzaNfOfdXMhCBPWNLGUefhossu8yUlPa9K5YVUlircfzjRegGT3hQYhaUB86Eo/A+q8Lh9 FyKa4e0if+oxWZxVJ/gYi8OJ+vHclbw/A6CDRpuHpMycMwJB4pNR6QVEd0Gvi7jbQGTdY01NUVmYY Rk6/snpw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lVumD-004Fyn-9X; Mon, 12 Apr 2021 11:30:49 +0000 Date: Mon, 12 Apr 2021 12:30:45 +0100 From: Matthew Wilcox To: Jan Kara Cc: Ted Tso , linux-ext4@vger.kernel.org, Eric Whitney , linux-fsdevel@vger.kernel.org, "Darrick J . Wong" Subject: Re: [PATCH 3/3] ext4: Fix overflow in ext4_iomap_alloc() Message-ID: <20210412113045.GI2531743@casper.infradead.org> References: <20210412102333.2676-1-jack@suse.cz> <20210412102333.2676-4-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210412102333.2676-4-jack@suse.cz> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Apr 12, 2021 at 12:23:33PM +0200, Jan Kara wrote: > A code in iomap alloc may overblock block number when converting it to "overflow"? > byte offset. Luckily this is mostly harmless as we will just use more > expensive method of writing using unwritten extents even though we are > writing beyond i_size. > > Fixes: 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure") > Signed-off-by: Jan Kara > --- > fs/ext4/inode.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 0948a43f1b3d..7cebbb2d2e34 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3420,7 +3420,7 @@ static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map, > * i_disksize out to i_size. This could be beyond where direct I/O is > * happening and thus expose allocated blocks to direct I/O reads. > */ > - else if ((map->m_lblk * (1 << blkbits)) >= i_size_read(inode)) > + else if (((loff_t)map->m_lblk << blkbits) >= i_size_read(inode)) > m_flags = EXT4_GET_BLOCKS_CREATE; > else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) > m_flags = EXT4_GET_BLOCKS_IO_CREATE_EXT; > -- > 2.26.2 >