From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756243AbdLGPwP (ORCPT ); Thu, 7 Dec 2017 10:52:15 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:23066 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499AbdLGPwK (ORCPT ); Thu, 7 Dec 2017 10:52:10 -0500 From: alexander.levin@verizon.com Cc: David Howells , alexander.levin@verizon.com X-Host: endeavour.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.9 061/156] afs: Fix the maths in afs_fs_store_data() Thread-Topic: [PATCH AUTOSEL for 4.9 061/156] afs: Fix the maths in afs_fs_store_data() Thread-Index: AQHTb3Lsyt0ufYw5V0+8OVv+M6W+LA== Date: Thu, 7 Dec 2017 15:49:10 +0000 Message-ID: <20171207154845.4814-61-alexander.levin@verizon.com> References: <20171207154845.4814-1-alexander.levin@verizon.com> In-Reply-To: <20171207154845.4814-1-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 vB7HJoTe026597 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 fed95c34bdc0..2ae86018fcb7 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -1178,7 +1178,7 @@ 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