Commit d82bccc6 authored Apr 12, 2016 by Alexei Starovoitov Committed by David S. Miller Apr 14, 2016

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: ddd872bc ("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>

parent 3dcd493f

kernel/bpf/verifier.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;

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