From patchwork Thu Mar 9 18:57:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 9613951 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0244F60417 for ; Thu, 9 Mar 2017 19:00:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EFB762864F for ; Thu, 9 Mar 2017 19:00:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E337A28655; Thu, 9 Mar 2017 19:00:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9354A2864F for ; Thu, 9 Mar 2017 19:00:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933162AbdCIS57 (ORCPT ); Thu, 9 Mar 2017 13:57:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45684 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932698AbdCIS5z (ORCPT ); Thu, 9 Mar 2017 13:57:55 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C6FB261D1B; Thu, 9 Mar 2017 18:57:55 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-66.rdu2.redhat.com [10.10.120.66] (may be forged)) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v29IvsAZ016216; Thu, 9 Mar 2017 13:57:54 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 18/27] afs: Fix the maths in afs_fs_store_data() From: David Howells To: viro@ZenIV.linux.org.uk Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 09 Mar 2017 18:57:53 +0000 Message-ID: <148908587311.16794.6013864468303097820.stgit@warthog.procyon.org.uk> In-Reply-To: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> References: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 09 Mar 2017 18:57:55 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP afs_fs_store_data() works out of the size of the write it's going to make, but it uses 32-bit unsigned subtraction in one place that gets automatically cast to loff_t. However, if to < offset, then the number goes negative, but as the result isn't signed, this doesn't get sign-extended to 64-bits when placed in a loff_t. Fix by casting the operands to loff_t. Signed-off-by: David Howells --- fs/afs/fsclient.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index 0778c5b6b59b..d9234b767287 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -1236,7 +1236,7 @@ int afs_fs_store_data(struct afs_server *server, struct afs_writeback *wb, _enter(",%x,{%x:%u},,", key_serial(wb->key), vnode->fid.vid, vnode->fid.vnode); - size = to - offset; + size = (loff_t)to - (loff_t)offset; if (first != last) size += (loff_t)(last - first) << PAGE_SHIFT; pos = (loff_t)first << PAGE_SHIFT;