crypto/ghash-generic.c in the Linux kernel before 3.1 allows local users to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact by triggering a failed or missing ghash_setkey function call, followed by a (1) ghash_update function call or (2) ghash_final function call, as demonstrated by a write operation on an AF_ALG socket.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=7ed47b7d142ec99ad6880bbbec51e9f12b3af74c
www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.1
www.openwall.com/lists/oss-security/2011/10/27/2
bugzilla.redhat.com/show_bug.cgi?id=749475
github.com/torvalds/linux/commit/7ed47b7d142ec99ad6880bbbec51e9f12b3af74c