When reading extended attributes, check e_value_offs to make sure that
it starts in the value area and not the name area. The attached test
case image will crash the kernel if it is mounted and you append more
than 4096 bytes of data to /a, due to insufficient validation.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>