| From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 59/66] bpf/verifier: reject invalid LD_ABS | BPF_DW instruction | Date | Tue, 26 Apr 2016 13:24:50 -0700 |
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3.19.8-ckt20 -stable review patch. If anyone has any objections, please let me know.
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From: Alexei Starovoitov <ast@fb.com>
commit d82bccc69041a51f7b7b9b4a36db0772f4cdba21 upstream.
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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- kernel/bpf/verifier.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7f68ff6..0d2cbc9 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1213,6 +1213,7 @@ 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; -- 2.7.4
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