From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753200AbdLGQ0C (ORCPT ); Thu, 7 Dec 2017 11:26:02 -0500 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:19368 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756142AbdLGP4p (ORCPT ); Thu, 7 Dec 2017 10:56:45 -0500 From: alexander.levin@verizon.com Cc: David Howells , alexander.levin@verizon.com X-Host: mariner.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 3.18 19/59] afs: Fix the maths in afs_fs_store_data() Thread-Topic: [PATCH AUTOSEL for 3.18 19/59] afs: Fix the maths in afs_fs_store_data() Thread-Index: AQHTb3M9HYynjb5m202LkY6W4NU/DQ== Date: Thu, 7 Dec 2017 15:51:27 +0000 Message-ID: <20171207155116.6013-19-alexander.levin@verizon.com> References: <20171207155116.6013-1-alexander.levin@verizon.com> In-Reply-To: <20171207155116.6013-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB7GQ7ZN006945 From: David Howells [ 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 c2e930ec2888..4abafa196d66 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -1225,7 +1225,7 @@ 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; -- 2.11.0