Re: [PATCH Resend] Bluetooth: virtio_bt: Use skb_put to set length

From: Luiz Augusto von Dentz
Date: Tue Jul 26 2022 - 14:56:57 EST


Hi Soenke,

On Sun, Jul 24, 2022 at 11:53 PM Soenke Huster <soenke.huster@xxxxxxxxx> wrote:
>
> By using skb_put we ensure that skb->tail is set
> correctly. Currently, skb->tail is always zero, which
> leads to errors, such as the following page fault in
> rfcomm_recv_frame:
>
> BUG: unable to handle page fault for address: ffffed1021de29ff
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> RIP: 0010:rfcomm_run+0x831/0x4040 (net/bluetooth/rfcomm/core.c:1751)

Please add the Fixes tag with the original patch that introduced the problem.

> Signed-off-by: Soenke Huster <soenke.huster@xxxxxxxxx>
> ---
> drivers/bluetooth/virtio_bt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/virtio_bt.c b/drivers/bluetooth/virtio_bt.c
> index 67c21263f9e0..fd281d439505 100644
> --- a/drivers/bluetooth/virtio_bt.c
> +++ b/drivers/bluetooth/virtio_bt.c
> @@ -219,7 +219,7 @@ static void virtbt_rx_work(struct work_struct *work)
> if (!skb)
> return;
>
> - skb->len = len;
> + skb_put(skb, len);
> virtbt_rx_handle(vbt, skb);
>
> if (virtbt_add_inbuf(vbt) < 0)
> --
> 2.36.1
>


--
Luiz Augusto von Dentz