commit784047eb2dupstream. The "len" could be as low as -14 so we should check for negatives. Fixes:9a7fe54ddc("staging: r8188eu: Add source files for new driver - part 1") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>