Commit 3a56ef71 authored by Pavel Skripkin's avatar Pavel Skripkin Committed by Marcel Holtmann
Browse files

Bluetooth: stop proccessing malicious adv data 



Syzbot reported slab-out-of-bounds read in hci_le_adv_report_evt(). The
problem was in missing validaion check.

We should check if data is not malicious and we can read next data block.
If we won't check ptr validness, code can read a way beyond skb->end and
it can cause problems, of course.

Fixes: e95beb41 ("Bluetooth: hci_le_adv_report_evt code refactoring")
Reported-and-tested-by: default avatar <syzbot+e3fcb9c4f3c2a931dc40@syzkaller.appspotmail.com>
Signed-off-by: default avatarPavel Skripkin <paskripkin@gmail.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent dd2ac1d6

net/bluetooth/hci_event.c

+7 −1
Original line number Diff line number Diff line
@@ -5906,7 +5906,8 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) 
		struct hci_ev_le_advertising_info *ev = ptr;

		s8 rssi;



		if (ev->length <= HCI_MAX_AD_LENGTH) {

		if (ev->length <= HCI_MAX_AD_LENGTH &&

		    ev->data + ev->length <= skb_tail_pointer(skb)) {

			rssi = ev->data[ev->length];

			process_adv_report(hdev, ev->evt_type, &ev->bdaddr,

					   ev->bdaddr_type, NULL, 0, rssi,
@@ -5916,6 +5917,11 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) 
		}



		ptr += sizeof(*ev) + ev->length + 1;



		if (ptr > (void *) skb_tail_pointer(skb) - sizeof(*ev)) {

			bt_dev_err(hdev, "Malicious advertising data. Stopping processing");

			break;

		}

	}



	hci_dev_unlock(hdev);