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Commit e67b8a68 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

bpf/verifier: reject BPF_ALU64|BPF_END 



Neither ___bpf_prog_run nor the JITs accept it.
Also adds a new test case.

Fixes: 17a52670 ("bpf: verifier (add verifier core)")
Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Acked-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 8c7c19a5

kernel/bpf/verifier.c

+2 −1
Original line number Diff line number Diff line
@@ -2292,7 +2292,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) 
			}

		} else {

			if (insn->src_reg != BPF_REG_0 || insn->off != 0 ||

			    (insn->imm != 16 && insn->imm != 32 && insn->imm != 64)) {

			    (insn->imm != 16 && insn->imm != 32 && insn->imm != 64) ||

			    BPF_CLASS(insn->code) == BPF_ALU64) {

				verbose("BPF_END uses reserved fields\n");

				return -EINVAL;

			}

tools/testing/selftests/bpf/test_verifier.c

+16 −0
Original line number Diff line number Diff line
@@ -6629,6 +6629,22 @@ static struct bpf_test tests[] = { 
		.result = REJECT,

		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,

	},

	{

		"invalid 64-bit BPF_END",

		.insns = {

			BPF_MOV32_IMM(BPF_REG_0, 0),

			{

				.code  = BPF_ALU64 | BPF_END | BPF_TO_LE,

				.dst_reg = BPF_REG_0,

				.src_reg = 0,

				.off   = 0,

				.imm   = 32,

			},

			BPF_EXIT_INSN(),

		},

		.errstr = "BPF_END uses reserved fields",

		.result = REJECT,

	},

};



static int probe_filter_length(const struct bpf_insn *fp)