From e67b8a685c7c984e834e3181ef4619cd7025a136 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Fri, 15 Sep 2017 14:37:38 +0100 Subject: [PATCH] bpf/verifier: reject BPF_ALU64|BPF_END Neither ___bpf_prog_run nor the JITs accept it. Also adds a new test case. Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Signed-off-by: Edward Cree Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- kernel/bpf/verifier.c | 3 ++- tools/testing/selftests/bpf/test_verifier.c | 16 ++++++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 477b693..799b245 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -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; } diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 8eb0995..26f3250 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -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) -- 2.7.4