When doing a listxattr on an inode which does not have i_op->listxattr defined
and you are giving the exact number of bytes required, the code wrongly
considers this value too small and instead returns ERANGE.

The bug was introduced in 2.6.14, I believe with:
 diff --git a/fs/xattr.c b/fs/xattr.c
 index 6acd5c6..3f9c64b 100644
in which the test in the fs/xattr.c file, line 246, is as follows:
        if (size && error >= size)
            error = -ERANGE;
However, the 'real' filesystems do the test only with >, since the 'error'
parameter is what is returned by this function and thus, when passed back as
'size', it should be accepted.

Fix: change the comparison to '>' only.

Regards,
Iustin Pop