The mm_for_maps function in fs/proc/base.c in the Linux kernel 2.6.30.4 and earlier allows local users to read (1) maps and (2) smaps files under proc/ via vectors related to ELF loading, a setuid process, and a race condition.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=00f89d218523b9bf6b522349c039d5ac80aa536d
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=13f0feafa6b8aead57a2a328e2fca6a5828bf286
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=704b836cbf19e885f8366bccb2e4b0474346c02d
lkml.org/lkml/2009/6/23/652
lkml.org/lkml/2009/6/23/653
marc.info/?l=linux-kernel&m=124718946021193
marc.info/?l=linux-kernel&m=124718949821250
secunia.com/advisories/36265
secunia.com/advisories/36501
www.debian.org/security/2010/dsa-2005
www.openwall.com/lists/oss-security/2009/08/11/1
www.securityfocus.com/bid/36019
www.vupen.com/english/advisories/2009/2246
bugzilla.redhat.com/show_bug.cgi?id=516171
exchange.xforce.ibmcloud.com/vulnerabilities/52401
rhn.redhat.com/errata/RHSA-2009-1540.html
www.redhat.com/archives/fedora-package-announce/2009-August/msg01256.html