From: Eric Sandeen <sandeen@redhat.com>
Date: Fri, 7 Feb 2014 04:26:11 +0000 (+1100)
Subject: xfs: sanitize sb_inopblock in xfs_mount_validate_sb
X-Git-Tag: v3.15-rc1~90^2~7^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=392c6de98af1fd7e2fc9c7bf5e52be16286f7b42;p=pandora-kernel.git

xfs: sanitize sb_inopblock in xfs_mount_validate_sb

xfs_mount_validate_sb doesn't check sb_inopblock for sanity
(as does its xfs_repair counterpart, FWIW).

If it's out of bounds, we can go off the rails in i.e.
xfs_inode_buf_verify(), which uses sb_inopblock as a loop
limit when stepping through a metadata buffer.

The problem can be demonstrated easily by corrupting
sb_inopblock with xfs_db and trying to mount the result:

# mkfs.xfs -dfile,name=fsfile,size=1g
# xfs_db -x fsfile
xfs_db> sb 0
xfs_db> write inopblock 512
inopblock = 512
xfs_db> quit

# mount -o loop fsfile  mnt
and we blow up in xfs_inode_buf_verify().

With this patch, we get a (very noisy) corruption error,
and fail the mount as we should.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
---

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