From 1ecb2cb0a1c3bef4ecbdb3354d123c55d0d776e2 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Sat, 9 Jan 2021 23:03:40 -0800
Subject: [PATCH] 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: 1e772326c4aa ("bpf: Load and verify kernel module BTFs")
Reported-by: Christopher William Snowhill <chris@kode54.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210110070341.1380086-1-andrii@kernel.org
---
kernel/bpf/btf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 8d6bdb4f4d618..84a36ee4a4c20 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -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;
}
--
2.39.5