From c77bbc8ea68a58f84cd40b881304ffa5127099d2 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Sat, 2 Jun 2018 09:06:51 -0700 Subject: [PATCH] bpf: btf: Ensure t->type == 0 for BTF_KIND_FWD The t->type in BTF_KIND_FWD is not used. It must be 0. This patch ensures that and also adds a test case in test_btf.c Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Signed-off-by: Cyber Knight --- kernel/bpf/btf.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index c2f583bd6d4c..9ce5b75987f6 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1240,8 +1240,27 @@ static struct btf_kind_operations ptr_ops = { .seq_show = btf_ptr_seq_show, }; +static s32 btf_fwd_check_meta(struct btf_verifier_env *env, + const struct btf_type *t, + u32 meta_left) +{ + if (btf_type_vlen(t)) { + btf_verifier_log_type(env, t, "vlen != 0"); + return -EINVAL; + } + + if (t->type) { + btf_verifier_log_type(env, t, "type != 0"); + return -EINVAL; + } + + btf_verifier_log_type(env, t, NULL); + + return 0; +} + static struct btf_kind_operations fwd_ops = { - .check_meta = btf_ref_type_check_meta, + .check_meta = btf_fwd_check_meta, .resolve = btf_df_resolve, .check_member = btf_df_check_member, .log_details = btf_ref_type_log,