Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

[linux-2.6-microblaze.git] / kernel / bpf / btf.c

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 4f2408a..4423045 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4928,6 +4928,7 @@ static int btf_check_type_tags(struct btf_verifier_env *env,
        n = btf_nr_types(btf);
        for (i = start_id; i < n; i++) {
                const struct btf_type *t;
+               int chain_limit = 32;
                u32 cur_id = i;
 
                t = btf_type_by_id(btf, i);
@@ -4940,6 +4941,10 @@ static int btf_check_type_tags(struct btf_verifier_env *env,
 
                in_tags = btf_type_is_type_tag(t);
                while (btf_type_is_modifier(t)) {
+                       if (!chain_limit--) {
+                               btf_verifier_log(env, "Max chain length or cycle detected");
+                               return -ELOOP;
+                       }
                        if (btf_type_is_type_tag(t)) {
                                if (!in_tags) {
                                        btf_verifier_log(env, "Type tags don't precede modifiers");