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| author | Alexei Starovoitov <ast@fb.com> | 2016-04-12 10:26:19 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-14 01:31:50 -0400 |
| commit | d82bccc69041a51f7b7b9b4a36db0772f4cdba21 (patch) | |
| tree | e7566bc2ab7ba1ec1bd316b87b62c128dbf63f18 /kernel/bpf/verifier.c | |
| parent | 3dcd493fbebfd631913df6e2773cc295d3bf7d22 (diff) | |
| download | lwn-d82bccc69041a51f7b7b9b4a36db0772f4cdba21.tar.gz lwn-d82bccc69041a51f7b7b9b4a36db0772f4cdba21.zip | |
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: ddd872bc3098 ("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>
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 2e08f8e9b771..618ef77c302a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -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 || + BPF_SIZE(insn->code) == BPF_DW || (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) { verbose("BPF_LD_ABS uses reserved fields\n"); return -EINVAL; |