The dvb_ca_ioctl function in drivers/media/dvb/ttpci/av7110_ca.c in the Linux kernel before 2.6.38-rc2 does not check the sign of a certain integer field, which allows local users to cause a denial of service (memory corruption) or possibly have unspecified other impact via a negative value.
http://openwall.com/lists/oss-security/2011/01/24/2
http://openwall.com/lists/oss-security/2011/01/25/2
http://secunia.com/advisories/43009
http://secunia.com/advisories/46397
http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.38-rc2
http://www.securityfocus.com/archive/1/520102/100/0/threaded
http://www.securityfocus.com/bid/45986
http://www.securitytracker.com/id?1025195
http://www.vmware.com/security/advisories/VMSA-2011-0012.html