commit 08ae93a2eda03817deabf08d4da9015a283ed56b
Author: Niu Yawei <niu@whamcloud.com>
Date: Sat Nov 19 23:08:03 2011 -0500

libext2fs: enforce a max nested link count in ext2fs_find_block_device()

Define EXT2FS_MAX_NESTED_LINKS as 8, and check the link count to make
sure we don't exceed it in ext2fs_find_block_device() and
follow_link(). This fixes a potential infinite loop in
ext2fs_find_block_device() if there are symbolic loop links in the
device directory.

Signed-off-by: Niu Yawei <niu@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>