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Commit d82bccc6 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller
Browse files

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: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid 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;