Hi Peilin,
> `num_reports` is not being properly checked. A malformed event packet with
> a large `num_reports` number makes hci_le_direct_adv_report_evt() read out
> of bounds. Fix it.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 2f010b55884e ("Bluetooth: Add support for handling LE Direct Advertising Report events")
> Reported-and-tested-by: syzbot+24ebd650e20bd263ca01@xxxxxxxxxxxxxxxxxxxxxxxxx
> Link: https://syzkaller.appspot.com/bug?extid=24ebd650e20bd263ca01
> Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
> ---
> Change in v2:
> - add "Cc: stable@" tag.
>
> net/bluetooth/hci_event.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 4b7fc430793c..aec43ae488d1 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -5863,21 +5863,19 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,
> struct sk_buff *skb)
> {
> u8 num_reports = skb->data[0];
> - void *ptr = &skb->data[1];
> + struct hci_ev_le_direct_adv_info *ev = (void *)&skb->data[1];
>
> - hci_dev_lock(hdev);
> + if (!num_reports || skb->len < num_reports * sizeof(*ev) + 1)
> + return;
>
> - while (num_reports--) {
> - struct hci_ev_le_direct_adv_info *ev = ptr;
> + hci_dev_lock(hdev);
>
> + for (; num_reports; num_reports--, ev++)
> process_adv_report(hdev, ev->evt_type, &ev->bdaddr,
> ev->bdaddr_type, &ev->direct_addr,
> ev->direct_addr_type, ev->rssi, NULL, 0,
> false);
>
> - ptr += sizeof(*ev);
> - }
> -
> hci_dev_unlock(hdev);
> }
patch has been applied to bluetooth-next tree.
Regards
Marcel
