The ABI in the Linux kernel 2.6.28 and earlier on s390, powerpc, sparc64, and mips 64-bit platforms requires that a 32-bit argument in a 64-bit register was properly sign extended when sent from a user-mode application, but cannot verify this, which allows local users to cause a denial of service (crash) or possibly gain privileges via a crafted system call.
lists.opensuse.org/opensuse-security-announce/2009-02/msg00003.html
marc.info/?l=linux-kernel&m=123155111608910&w=2
secunia.com/advisories/33477
secunia.com/advisories/33674
secunia.com/advisories/34394
secunia.com/advisories/34981
secunia.com/advisories/35011
www.debian.org/security/2009/dsa-1749
www.debian.org/security/2009/dsa-1787
www.debian.org/security/2009/dsa-1794
www.mandriva.com/security/advisories?name=MDVSA-2009:135
www.securityfocus.com/bid/33275
bugzilla.redhat.com/show_bug.cgi?id=479969
www.redhat.com/archives/fedora-package-announce/2009-January/msg01045.html