From: Mykyta Yatsenko <yatsenko@xxxxxxxx>
Avoid dereferencing bpf_map_skeleton's link field if it's NULL.
If BPF map skeleton is created with the size, that indicates containing
link field, but the field was not actually initialized with valid
bpf_link pointer, libbpf crashes. This may happen when using libbpf-rs
skeleton.
Skeleton loading may still progress, but user needs to attach struct_ops
map separately.
Signed-off-by: Mykyta Yatsenko <yatsenko@xxxxxxxx>
---
tools/lib/bpf/libbpf.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 617cfb9a7ff5..e9c641a2fb20 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -14102,6 +14102,12 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
}
link = map_skel->link;
+ if (!link) {
+ pr_warn("map '%s': BPF map skeleton link is uninitialized\n",
+ bpf_map__name(map));
+ continue;
+ }
+
if (*link)
continue;
--
2.49.0
