The hso_get_count function in drivers/net/usb/hso.c in the Linux kernel before 2.6.36-rc5 does not properly initialize a certain structure member, which allows local users to obtain potentially sensitive information from kernel stack memory via a TIOCGICOUNT ioctl call.
https://bugzilla.redhat.com/show_bug.cgi?id=633140
http://www.vupen.com/english/advisories/2011/0298
http://www.vupen.com/english/advisories/2011/0070
http://www.ubuntu.com/usn/USN-1041-1
http://www.securityfocus.com/bid/43226
http://www.redhat.com/support/errata/RHSA-2011-0007.html
http://www.openwall.com/lists/oss-security/2010/09/14/7
http://www.openwall.com/lists/oss-security/2010/09/14/2
http://secunia.com/advisories/42890
http://secunia.com/advisories/42758
http://secunia.com/advisories/41440
http://lkml.org/lkml/2010/9/11/167
http://lists.opensuse.org/opensuse-security-announce/2011-02/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2010-10/msg00003.html