The ext4_fill_super 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 filesystem.
CWE-20