Published: 30 September 2010
The cxgb_extension_ioctl function in drivers/net/cxgb3/cxgb3_main.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 CHELSIO_GET_QSET_NUM ioctl call.
From the Ubuntu security team
Dan Rosenberg discovered that several network ioctls did not clear kernel memory correctly. A local user could exploit this to read kernel stack memory, leading to a loss of privacy.