Linux kernel 2.2.x allows local users to cause a denial of service (crash) by using the mmap() function with a PROT_READ parameter to access non-readable memory pages through the /proc/pid/mem interface.
https://exchange.xforce.ibmcloud.com/vulnerabilities/10884
http://www.trustix.net/errata/misc/2002/TSL-2002-0083-kernel.asc.txt
http://www.redhat.com/support/errata/RHSA-2003-088.html
http://www.mandrakesoft.com/security/advisories?name=MDKSA-2003:039
http://www.linuxsecurity.com/advisories/engarde_advisory-2976.html