Daniel Borkmann 342332fb0b bpf: Don't promote bogus looking registers after null check.
[ Upstream commit e60b0d12a95dcf16a63225cead4541567f5cb517 ]

If we ever get to a point again where we convert a bogus looking <ptr>_or_null
typed register containing a non-zero fixed or variable offset, then lets not
reset these bounds to zero since they are not and also don't promote the register
to a <ptr> type, but instead leave it as <ptr>_or_null. Converting to a unknown
register could be an avenue as well, but then if we run into this case it would
allow to leak a kernel pointer this way.

Fixes: f1174f77b50c ("bpf/verifier: rework value tracking")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 10:54:00 +01:00
..
2021-04-14 08:41:58 +02:00
2020-08-12 10:58:02 -07:00
2020-11-14 11:26:04 -08:00
2020-07-27 14:31:12 -04:00