Race condition in the find_keyring_by_name function in security/keys/keyring.c in the Linux kernel 2.6.34-rc5 and earlier allows local users to cause a denial of service (memory corruption and system crash) or possibly have unspecified other impact via keyctl session commands that trigger access to a dead keyring that is undergoing deletion by the key_cleanup function.
https://exchange.xforce.ibmcloud.com/vulnerabilities/58254
http://www.vmware.com/security/advisories/VMSA-2011-0003.html
http://www.openwall.com/lists/oss-security/2010/04/28/2
http://www.openwall.com/lists/oss-security/2010/04/27/2
http://www.debian.org/security/2010/dsa-2053
http://marc.info/?l=linux-kernel&m=127292492727029&w=2
http://lists.opensuse.org/opensuse-security-announce/2010-07/msg00006.html