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.
bugzilla.kernel.org/show_bug.cgi?id=12371
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=4ec110281379826c5cf6ed14735e47027c3c5765
kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.27.19
kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.28.7
osvdb.org/52203
rhn.redhat.com/errata/RHSA-2009-1243.html
secunia.com/advisories/34394
secunia.com/advisories/36562
secunia.com/advisories/37471
www.debian.org/security/2009/dsa-1749
www.securityfocus.com/archive/1/507985/100/0/threaded
www.ubuntu.com/usn/usn-751-1
www.vmware.com/security/advisories/VMSA-2009-0016.html
www.vupen.com/english/advisories/2009/0509
www.vupen.com/english/advisories/2009/3316
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10683
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8526