Re: [syzbot] [bluetooth?] KASAN: invalid-free in hci_req_sync_complete

[Edward Adam Davis]

please test db free in hci_req_sync_complete

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2ccbdf43d5e7

diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 3862fa6bb288..4d5807fff946 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -121,6 +121,7 @@ int __hci_req_sync(struct hci_dev *hdev, int (*func)(struct hci_request *req,
 {
 	struct hci_request req;
 	int err = 0;
+	struct sk_buff	*req_skb;
 
 	bt_dev_dbg(hdev, "start");
 
@@ -182,8 +183,9 @@ int __hci_req_sync(struct hci_dev *hdev, int (*func)(struct hci_request *req,
 		break;
 	}
 
-	kfree_skb(hdev->req_skb);
+	req_skb = hdev->req_skb;
 	hdev->req_skb = NULL;
+	kfree_skb(req_skb);
 	hdev->req_status = hdev->req_result = 0;
 
 	bt_dev_dbg(hdev, "end: err %d", err);