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>
Eric Sandeen