[PATCHv2] net: bpf: reject invalid shifts

On Tue, Jan 12, 2016 at 08:17:08PM +0100, Rabin Vincent wrote:

On ARM64, a BUG() is triggered in the eBPF JIT if a filter with a
constant shift that can't be encoded in the immediate field of the
UBFM/SBFM instructions is passed to the JIT.  Since these shifts
amounts, which are negative or >= regsize, are invalid, reject them in
the eBPF verifier and the classic BPF filter checker, for all
architectures.

Signed-off-by: Rabin Vincent <redacted>
---
v2: handle BPF_ARSH too

Thanks.
Acked-by: Alexei Starovoitov <ast@kernel.org>