linux-kernel - [PATCH AUTOSEL for 4.4 29/32] xen/gntdev: Fix off-by-one error when unmapping with holes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180203180413.7438-29-alexander.levin@microsoft.com>
Date:   Sat, 3 Feb 2018 18:04:40 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
CC:     Ross Lagerwall <ross.lagerwall@...rix.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 4.4 29/32] xen/gntdev: Fix off-by-one error when
 unmapping with holes

From: Ross Lagerwall <ross.lagerwall@...rix.com>

[ Upstream commit 951a010233625b77cde3430b4b8785a9a22968d1 ]

If the requested range has a hole, the calculation of the number of
pages to unmap is off by one. Fix it.

Signed-off-by: Ross Lagerwall <ross.lagerwall@...rix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
---
 drivers/xen/gntdev.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a4d749665c9f..44a9d8eb0eb4 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -378,10 +378,8 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
 		}
 		range = 0;
 		while (range < pages) {
-			if (map->unmap_ops[offset+range].handle == -1) {
-				range--;
+			if (map->unmap_ops[offset+range].handle == -1)
 				break;
-			}
 			range++;
 		}
 		err = __unmap_grant_pages(map, offset, range);
-- 
2.11.0