netdev - Re: [PATCH bpf 1/4] bpf: fix partial copy of map

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Date:   Thu, 1 Nov 2018 19:17:29 +0000
From:   Edward Cree <ecree@...arflare.com>
To:     Daniel Borkmann <daniel@...earbox.net>, <ast@...nel.org>
CC:     <netdev@...r.kernel.org>
Subject: Re: [PATCH bpf 1/4] bpf: fix partial copy of map_ptr when dst is
 scalar

On 31/10/18 23:05, Daniel Borkmann wrote:
> ALU operations on pointers such as scalar_reg += map_value_ptr are
> handled in adjust_ptr_min_max_vals(). Problem is however that map_ptr
> and range in the register state share a union, so transferring state
> through dst_reg->range = ptr_reg->range is just buggy as any new
> map_ptr in the dst_reg is then truncated (or null) for subsequent
> checks. Fix this by adding a raw member and use it for copying state
> over to dst_reg.
>
> Fixes: f1174f77b50c ("bpf/verifier: rework value tracking")
> Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
> Cc: Edward Cree <ecree@...arflare.com>
> Acked-by: Alexei Starovoitov <ast@...nel.org>
> ---
Acked-by: Edward Cree <ecree@...arflare.com>
(though I apparently missed the 63-minute window to hit the git record...)