diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-11-01 00:05:52 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-10-31 16:53:17 -0700 |
| commit | 0962590e553331db2cc0aef2dc35c57f6300dbbe (patch) | |
| tree | 8b206dfaa37c6d4efb244768dcdd25893a27902d /kernel | |
| parent | 3615353218744bb60f55170c620ce4dce1a008c7 (diff) | |
| download | linux-0962590e553331db2cc0aef2dc35c57f6300dbbe.tar.bz2 | |
bpf: fix partial copy of map_ptr when dst is scalar
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 171a2c88e77d..774fa40a32ae 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3046,7 +3046,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, dst_reg->umax_value = umax_ptr; dst_reg->var_off = ptr_reg->var_off; dst_reg->off = ptr_reg->off + smin_val; - dst_reg->range = ptr_reg->range; + dst_reg->raw = ptr_reg->raw; break; } /* A new variable offset is created. Note that off_reg->off @@ -3076,10 +3076,11 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, } dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off); dst_reg->off = ptr_reg->off; + dst_reg->raw = ptr_reg->raw; if (reg_is_pkt_pointer(ptr_reg)) { dst_reg->id = ++env->id_gen; /* something was added to pkt_ptr, set range to zero */ - dst_reg->range = 0; + dst_reg->raw = 0; } break; case BPF_SUB: @@ -3108,7 +3109,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, dst_reg->var_off = ptr_reg->var_off; dst_reg->id = ptr_reg->id; dst_reg->off = ptr_reg->off - smin_val; - dst_reg->range = ptr_reg->range; + dst_reg->raw = ptr_reg->raw; break; } /* A new variable offset is created. If the subtrahend is known @@ -3134,11 +3135,12 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, } dst_reg->var_off = tnum_sub(ptr_reg->var_off, off_reg->var_off); dst_reg->off = ptr_reg->off; + dst_reg->raw = ptr_reg->raw; if (reg_is_pkt_pointer(ptr_reg)) { dst_reg->id = ++env->id_gen; /* something was added to pkt_ptr, set range to zero */ if (smin_val < 0) - dst_reg->range = 0; + dst_reg->raw = 0; } break; case BPF_AND: |