Stack-based buffer overflow in the is_git_directory function in setup.c in Git before 1.7.2.1 allows local users to gain privileges via a long gitdir: field in a .git file in a working copy.
https://bugzilla.redhat.com/show_bug.cgi?id=618108
http://www.vupen.com/english/advisories/2011/0464
http://www.securityfocus.com/bid/41891
http://www.openwall.com/lists/oss-security/2010/07/22/4
http://www.openwall.com/lists/oss-security/2010/07/22/1
http://secunia.com/advisories/43457
http://lists.opensuse.org/opensuse-security-announce/2011-02/msg00004.html
http://git.kernel.org/?p=git/git.git%3Ba=commit%3Bh=3c9d0414ed2db0167e6c828b547be8fc9f88fccc