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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>,
	xfs@oss.sgi.com, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [patch] xfs: check for underflow in xfs_iformat_fork()
Date: Thu, 15 Aug 2013 08:53:38 +0300	[thread overview]
Message-ID: <20130815055338.GC23580@elgon.mountain> (raw)

The "di_size" variable comes from the disk and it's a signed 64 bit.
We check the upper limit but we should check for negative numbers as
well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/fs/xfs/xfs_inode_fork.c b/fs/xfs/xfs_inode_fork.c
index 123971b..849fc70 100644
--- a/fs/xfs/xfs_inode_fork.c
+++ b/fs/xfs/xfs_inode_fork.c
@@ -167,7 +167,8 @@ xfs_iformat_fork(
 			}
 
 			di_size = be64_to_cpu(dip->di_size);
-			if (unlikely(di_size > XFS_DFORK_DSIZE(dip, ip->i_mount))) {
+			if (unlikely(di_size < 0 ||
+				     di_size > XFS_DFORK_DSIZE(dip, ip->i_mount))) {
 				xfs_warn(ip->i_mount,
 			"corrupt inode %Lu (bad size %Ld for local inode).",
 					(unsigned long long) ip->i_ino,

             reply	other threads:[~2013-08-15  5:53 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-15  5:53 Dan Carpenter [this message]
2013-08-15 10:10 ` [patch] xfs: check for underflow in xfs_iformat_fork() Jeff Liu
2013-08-15 14:37   ` Ben Myers
2013-08-15 15:47     ` Dan Carpenter
2013-08-15 22:26     ` Dave Chinner
2013-08-23 17:36       ` Ben Myers
2013-08-26 14:37         ` Dan Carpenter
2013-08-26 16:12           ` Ben Myers

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