Null pointer dereference

The ext4fillsuper function in fs/ext4/super.c in the Linux kernel 2.6.27 before 2.6.27.19 and 2.6.28 before 2.6.28.7 does not validate the superblock configuration, which allows local users to cause a denial of service NULL pointer dereference and OOPS by attempting to mount a crafted ext4...