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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 BEF63C43603 for ; Wed, 18 Dec 2019 12:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B5D92146E for ; Wed, 18 Dec 2019 12:43:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726913AbfLRMnt (ORCPT ); Wed, 18 Dec 2019 07:43:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:37708 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725930AbfLRMns (ORCPT ); Wed, 18 Dec 2019 07:43:48 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 3E329B175; Wed, 18 Dec 2019 12:43:47 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id D99C21E0B2D; Wed, 18 Dec 2019 13:43:46 +0100 (CET) Date: Wed, 18 Dec 2019 13:43:46 +0100 From: Jan Kara To: Andreas Gruenbacher Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH] fs: Fix overflow in block_page_mkwrite Message-ID: <20191218124346.GC19387@quack2.suse.cz> References: <20191106190239.20860-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191106190239.20860-1-agruenba@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed 06-11-19 20:02:39, Andreas Gruenbacher wrote: > On architectures where ssize_t is wider than pgoff_t, the expression > ((page->index + 1) << PAGE_SHIFT) can overflow. Rewrite to use the page > offset, which we already compute here anyway. > > Signed-off-by: Andreas Gruenbacher This patch seems to have fallen through the cracks? Al? Honza > --- > fs/buffer.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/fs/buffer.c b/fs/buffer.c > index 86a38b979323..da3f33b70249 100644 > --- a/fs/buffer.c > +++ b/fs/buffer.c > @@ -2459,21 +2459,21 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, > struct page *page = vmf->page; > struct inode *inode = file_inode(vma->vm_file); > unsigned long end; > - loff_t size; > + loff_t offset, size; > int ret; > > lock_page(page); > size = i_size_read(inode); > - if ((page->mapping != inode->i_mapping) || > - (page_offset(page) > size)) { > + offset = page_offset(page); > + if (page->mapping != inode->i_mapping || offset > size) { > /* We overload EFAULT to mean page got truncated */ > ret = -EFAULT; > goto out_unlock; > } > > /* page is wholly or partially inside EOF */ > - if (((page->index + 1) << PAGE_SHIFT) > size) > - end = size & ~PAGE_MASK; > + if (offset > size - PAGE_SIZE) > + end = offset_in_page(size); > else > end = PAGE_SIZE; > > -- > 2.20.1 > -- Jan Kara SUSE Labs, CR