From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-sn1nam01on0125.outbound.protection.outlook.com ([104.47.32.125]:4176 "EHLO NAM01-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753956AbeARVGN (ORCPT ); Thu, 18 Jan 2018 16:06:13 -0500 From: Sasha Levin To: "stable@vger.kernel.org" , "stable-commits@vger.kernel.org" CC: David Howells , Sasha Levin Subject: [added to the 4.1 stable tree] afs: Fix the maths in afs_fs_store_data() Date: Thu, 18 Jan 2018 21:01:34 +0000 Message-ID: <20180118205908.3220-244-alexander.levin@microsoft.com> References: <20180118205908.3220-1-alexander.levin@microsoft.com> In-Reply-To: <20180118205908.3220-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: David Howells This patch has been added to the stable tree. If you have any objections, please let us know. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ Upstream commit 146a1192783697810b63a1e41c4d59fc93387340 ] 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 Signed-off-by: Sasha Levin --- 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 c775fefe3ffe..0c8399e0fdac 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -1225,7 +1225,7 @@ int afs_fs_store_data(struct afs_server *server, stru= ct afs_writeback *wb, _enter(",%x,{%x:%u},,", key_serial(wb->key), vnode->fid.vid, vnode->fid.vnode); =20 - size =3D to - offset; + size =3D (loff_t)to - (loff_t)offset; if (first !=3D last) size +=3D (loff_t)(last - first) << PAGE_SHIFT; pos =3D (loff_t)first << PAGE_SHIFT; --=20 2.11.0