On 9/12/18 10:29 AM, Martin KaFai Lau wrote:
The end boundary math for type section is incorrect in
btf_check_all_metas(). It just happens that hdr->type_off
is always 0 for now because there are only two sections
(type and string) and string section must be at the end (ensured
in btf_parse_str_sec).
However, type_off may not be 0 if a new section would be added later.
This patch fixes it.
Fixes: f80442a4cd18 ("bpf: btf: Change how section is supported in btf_header")
Reported-by: Dmitry Vyukov <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Acked-by: Yonghong Song <[email protected]>
---
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 2590700237c1..138f0302692e 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -1844,7 +1844,7 @@ static int btf_check_all_metas(struct btf_verifier_env
*env)
hdr = &btf->hdr;
cur = btf->nohdr_data + hdr->type_off;
- end = btf->nohdr_data + hdr->type_len;
+ end = cur + hdr->type_len;
env->log_type_id = 1;
while (cur < end) {
