The processcompl_compat function in drivers/usb/core/devio.c in Linux kernel 2.6.x through 2.6.32, and possibly other versions, does not clear the transfer buffer before returning to userspace when a USB command fails, which might make it easier for physically proximate attackers to obtain sensitive information (kernel memory).
Related bugs and status
CVE-2010-1083 (Candidate)
is related to these bugs: