linux-kernel - [PATCH 6/8] xfs: fix unsigned underflow

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-next>] [day] [month] [year] [list]

Message-Id: <1279219605-12631-1-git-send-email-segooon@gmail.com>
Date:	Thu, 15 Jul 2010 22:46:45 +0400
From:	Kulikov Vasiliy <segooon@...il.com>
To:	kernel-janitors@...r.kernel.org
Cc:	Alex Elder <aelder@....com>, xfs-masters@....sgi.com,
	Christoph Hellwig <hch@....de>,
	Dave Chinner <dchinner@...hat.com>,
	Felix Blyakher <felixb@....com>, xfs@....sgi.com,
	linux-kernel@...r.kernel.org
Subject: [PATCH 6/8] xfs: fix unsigned underflow

map_len is unsigned. Checking map_len <= 0 is buggy when it should be
below zero. So, check exact expression instead of map_len.

Signed-off-by: Kulikov Vasiliy <segooon@...il.com>
---
 fs/xfs/xfs_vnodeops.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 65e0879..66d585c 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -591,9 +591,9 @@ xfs_free_eofblocks(
 	 */
 	end_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)ip->i_size));
 	last_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
-	map_len = last_fsb - end_fsb;
-	if (map_len <= 0)
+	if (last_fsb <= end_fsb)
 		return 0;
+	map_len = last_fsb - end_fsb;
 
 	nimaps = 1;
 	xfs_ilock(ip, XFS_ILOCK_SHARED);
-- 
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/