Bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt()

peilin-ye · holtmann · commit 51c19bf3d5cf · 2020-07-10T19:08:32.000+02:00
Check upon `num_rsp` is insufficient. A malformed event packet with a large `num_rsp` number makes hci_extended_inquiry_result_evt() go out of bounds. Fix it. This patch fixes the following syzbot bug: https://syzkaller.appspot.com/bug?id=4bf11aa05c4ca51ce0df86e500fce486552dc8d2 Reported-by: syzbot+d8489a79b781849b9c46@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
@@ -4375,7 +4375,7 @@ static void hci_extended_inquiry_result_evt(struct hci_dev *hdev,
 
 	BT_DBG("%s num_rsp %d", hdev->name, num_rsp);
 
-	if (!num_rsp)
+	if (!num_rsp || skb->len < num_rsp * sizeof(*info) + 1)
 		return;
 
 	if (hci_dev_test_flag(hdev, HCI_PERIODIC_INQ))
