A numeric casting discrepancy in sdla_xfer in Linux kernel 2.6.x up to 2.6.5 and 2.4 up to 2.4.29-rc1 allows local users to read portions of kernel memory via a large len argument, which is received as an int but cast to a short, which prevents a read loop from filling a buffer.
http://secunia.com/advisories/18977
http://secunia.com/advisories/19369
http://www.debian.org/security/2006/dsa-1018
http://www.mandriva.com/security/advisories?name=MDKSA-2006:072
http://wwwnew.mandriva.com/security/advisories?name=MDKSA-2006:044