From: Martin KaFai Lau <redacted>
Date: Wed, 28 Jun 2017 10:41:24 -0700

The index is off-by-one when fp->aux->stack_depth
has already been rounded up to 32.  In particular,
if stack_depth is 512, the index will be 16.

The fix is to round_up and then takes -1 instead of round_down.

 ...

Fixes: b870aa901f4b ("bpf: use different interpreter depending on required stack size")
Signed-off-by: Martin KaFai Lau <redacted>
Acked-by: Alexei Starovoitov <redacted>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

Applied, thanks Martin.