Re: [PATCH] Bluetooth: btintel_pcie: validate completion ring indices

[Luiz Augusto von Dentz]

Hi @Kiran K

On Tue, Mar 24, 2026 at 4:51 AM Pengpeng Hou <pengpeng@xxxxxxxxxxx> wrote:
>
> The MSI-X RX and TX completion handlers trust the shared ring indices
> read from data->ia.cr_tia[] and data->ia.cr_hia[] before using cr_tia as
> an index into the fixed urbd ring arrays. If the device reports a stale
> or malformed completion index, the driver can step past rxq->urbd1s[] or
> txq->urbd0s[] before it gets a chance to recover.
>
> Validate both completion ring indices against the queue depth before
> walking the descriptor arrays.
>
> Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
> ---
>  drivers/bluetooth/btintel_pcie.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
> index 37b744e35bc4..06c2b81f2b6e 100644
> --- a/drivers/bluetooth/btintel_pcie.c
> +++ b/drivers/bluetooth/btintel_pcie.c
> @@ -1008,6 +1008,13 @@ static void btintel_pcie_msix_tx_handle(struct btintel_pcie_data *data)
>
>         txq = &data->txq;
>
> +       if (cr_tia >= txq->count || cr_hia >= txq->count) {
> +               bt_dev_err(data->hdev,
> +                          "TXQ: invalid ring indices tia=%u hia=%u",
> +                          cr_tia, cr_hia);
> +               return;
> +       }
> +
>         while (cr_tia != cr_hia) {
>                 data->tx_wait_done = true;
>                 wake_up(&data->tx_wait_q);
> @@ -1403,6 +1410,12 @@ static void btintel_pcie_msix_rx_handle(struct btintel_pcie_data *data)
>
>         rxq = &data->rxq;
>
> +       if (cr_tia >= rxq->count || cr_hia >= rxq->count) {
> +               bt_dev_err(hdev, "RXQ: invalid ring indices tia=%u hia=%u",
> +                          cr_tia, cr_hia);
> +               return;
> +       }
> +
>         /* The firmware sends multiple CD in a single MSI-X and it needs to
>          * process all received CDs in this interrupt.
>          */
> --
> 2.50.1 (Apple Git-155)

Can you review these changes?

-- 
Luiz Augusto von Dentz