bpf/verifier: reject invalid LD_ABS | BPF_DW instruction

verifier must check for reserved size bits in instruction opcode and
reject BPF_LD | BPF_ABS | BPF_DW and BPF_LD | BPF_IND | BPF_DW instructions,
otherwise interpreter will WARN_RATELIMIT on them during execution.

Fixes: ddd872bc30 ("bpf: verifier: add checks for BPF_ABS | BPF_IND instructions")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov 2016-04-12 10:26:19 -07:00 committed by David S. Miller
parent 3dcd493fbe
commit d82bccc690
1 changed files with 1 additions and 0 deletions

View File

@ -1374,6 +1374,7 @@ static int check_ld_abs(struct verifier_env *env, struct bpf_insn *insn)
} }
if (insn->dst_reg != BPF_REG_0 || insn->off != 0 || if (insn->dst_reg != BPF_REG_0 || insn->off != 0 ||
BPF_SIZE(insn->code) == BPF_DW ||
(mode == BPF_ABS && insn->src_reg != BPF_REG_0)) { (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) {
verbose("BPF_LD_ABS uses reserved fields\n"); verbose("BPF_LD_ABS uses reserved fields\n");
return -EINVAL; return -EINVAL;