[PATCHv2] net: bpf: reject invalid shifts

[David Miller]

From: Eric Dumazet <eric.dumazet at gmail.com>
Date: Tue, 12 Jan 2016 20:07:44 -0800

> On Tue, 2016-01-12 at 21:43 -0500, David Miller wrote:
>> From: Eric Dumazet <eric.dumazet at gmail.com>
>> Date: Tue, 12 Jan 2016 18:11:38 -0800
>> 
>> > 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.

I guess you are uninterested in knowing your programs contains such
garbage.