[PATCHv2] net: bpf: reject invalid shifts

On Tue, 2016-01-12 at 21:43 -0500, David Miller wrote:

From: Eric Dumazet <redacted>
Date: Tue, 12 Jan 2016 18:11:38 -0800

quoted

As I said, it is possible some guys never noticed their BPF program
were 'broken' because this invalid shift was hidden in a dead code
part.

We should not hide bugs and unintended uses of operations with
undefined behavior.

   JUMP 2:
   SHR  45
2: RET  10


was a valid program.

But a dumb loader decided to know better.