--- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -230,7 +230,7 @@ static long __bpf_get_stackid(struct bpf_map *map, struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); struct stack_map_bucket *bucket, *new_bucket, *old_bucket; u32 skip = flags & BPF_F_SKIP_FIELD_MASK; - u32 hash, id, trace_nr, trace_len, i; + u32 hash, id, trace_nr, trace_len, i, max_depth; bool user = flags & BPF_F_USER_STACK; u64 *ips; bool hash_matches; @@ -241,6 +241,19 @@ static long __bpf_get_stackid(struct bpf_map *map, trace_nr = trace->nr - skip; trace_len = trace_nr * sizeof(u64); + + /* Clamp the trace to max allowed depth */ + if (stack_map_use_build_id(map)) + max_depth = smap->map.value_size / sizeof(struct bpf_stack_build_id); + else + max_depth = smap->map.value_size / sizeof(u64); + + if (trace_nr > max_depth) + trace_nr = max_depth; + + ips = trace->ip + skip; + + ips = trace->ip + skip; hash = jhash2((u32 *)ips, trace_len / sizeof(u32), 0); id = hash & (smap->n_buckets - 1);