Commit bcc5e616 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

bpf: Allow empty module BTFs 



Some modules don't declare any new types and end up with an empty BTF,
containing only valid BTF header and no types or strings sections. This
currently causes BTF validation error. There is nothing wrong with such BTF,
so fix the issue by allowing module BTFs with no types or strings.

Fixes: 36e68442 ("bpf: Load and verify kernel module BTFs")
Reported-by: default avatarChristopher William Snowhill <chris@kode54.net>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210110070341.1380086-1-andrii@kernel.org
parent 4be34f3d

kernel/bpf/btf.c

+1 −1
Original line number Diff line number Diff line
@@ -4172,7 +4172,7 @@ static int btf_parse_hdr(struct btf_verifier_env *env) 
		return -ENOTSUPP;

	}



	if (btf_data_size == hdr->hdr_len) {

	if (!btf->base_btf && btf_data_size == hdr->hdr_len) {

		btf_verifier_log(env, "No data");

		return -EINVAL;

	}