Re: [PATCH] Bluetooth: hci_event: Add missing locking on hdev in hci_le_ext_adv_term_evt

From: Marcel Holtmann
Date: Fri Mar 04 2022 - 10:30:25 EST


Hi Niels,

> Both hci_find_adv_instance and hci_remove_adv_instance have a comment
> above their function definition saying that these two functions require
> the caller to hold the hdev->lock lock. However, hci_le_ext_adv_term_evt
> does not acquire that lock and neither does its caller hci_le_meta_evt
> (hci_le_meta_evt calls hci_le_ext_adv_term_evt via an indirect function
> call because of the lookup in hci_le_ev_table).
>
> The other event handlers all acquire and release the hdev->lock and they
> follow the rule that hci_find_adv_instance and hci_remove_adv_instance
> must be called while holding the hdev->lock lock.
>
> The solution is to make sure hci_le_ext_adv_term_evt also acquires and
> releases the hdev->lock lock. The check on ev->status which logs a
> warning and does an early return is not covered by the lock because
> other functions also access ev->status without holding the lock.
>
> Signed-off-by: Niels Dossche <niels.dossche@xxxxxxxx>
> ---
> net/bluetooth/hci_event.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel