OSDN Git Service

bpf: fix partial copy of map_ptr when dst is scalar
authorDaniel Borkmann <daniel@iogearbox.net>
Thu, 1 Nov 2018 21:29:53 +0000 (22:29 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 13 Nov 2018 19:08:14 +0000 (11:08 -0800)
commitd93080cdba60ec99db81f1c96d4b8dd8f0c3d7f9
tree63c6faa5c5c36c786622fc1ee94f63c2274144b3
parent07a03b97b9ce2a6430344386eeab9b16283b893f
bpf: fix partial copy of map_ptr when dst is scalar

commit 0962590e553331db2cc0aef2dc35c57f6300dbbe upstream.

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@iogearbox.net>
Cc: Edward Cree <ecree@solarflare.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
include/linux/bpf_verifier.h
kernel/bpf/verifier.c