Commit acd34cfc authored by Benjamin Tissoires's avatar Benjamin Tissoires
Browse files

HID: bpf: prevent the same struct_ops to be attached more than once 

If the struct_ops is already attached, we should bail out or we will
end up in various locks and pointer issues while unregistering.

Link: https://patch.msgid.link/20240723-fix-6-11-bpf-v1-3-b9d770346784@kernel.org


Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent f64c1a45

drivers/hid/bpf/hid_bpf_struct_ops.c

+5 −0
Original line number Diff line number Diff line
@@ -183,6 +183,10 @@ static int hid_bpf_reg(void *kdata, struct bpf_link *link) 
	struct hid_device *hdev;

	int count, err = 0;



	/* prevent multiple attach of the same struct_ops */

	if (ops->hdev)

		return -EINVAL;



	hdev = hid_get_device(ops->hid_id);

	if (IS_ERR(hdev))

		return PTR_ERR(hdev);
@@ -248,6 +252,7 @@ static void hid_bpf_unreg(void *kdata, struct bpf_link *link) 


	list_del_rcu(&ops->list);

	synchronize_srcu(&hdev->bpf.srcu);

	ops->hdev = NULL;



	reconnect = hdev->bpf.rdesc_ops == ops;

	if (reconnect)