On 24-02-02 10:42:17, Frank Li wrote:
> 829 if (request->complete) {
> 830 spin_unlock(&priv_dev->lock);
> 831 usb_gadget_giveback_request(&priv_ep->endpoint,
> 832 request);
> 833 spin_lock(&priv_dev->lock);
> 834 }
> 835
> 836 if (request->buf == priv_dev->zlp_buf)
> 837 cdns3_gadget_ep_free_request(&priv_ep->endpoint, request);
>
> Driver append an additional zero packet request when queue a packet, which
> length mod max packet size is 0. When transfer complete, run to line 831,
> usb_gadget_giveback_request() will free this requestion. 836 condition is
> true, so cdns3_gadget_ep_free_request() free this request again.
>
> Log:
>
> [ 1920.140696][ T150] BUG: KFENCE: use-after-free read in cdns3_gadget_giveback+0x134/0x2c0 [cdns3]
> [ 1920.140696][ T150]
> [ 1920.151837][ T150] Use-after-free read at 0x000000003d1cd10b (in kfence-#36):
> [ 1920.159082][ T150] cdns3_gadget_giveback+0x134/0x2c0 [cdns3]
> [ 1920.164988][ T150] cdns3_transfer_completed+0x438/0x5f8 [cdns3]
>
> Add check at line 829, skip call usb_gadget_giveback_request() if it is
> additional zero length packet request. Needn't call
> usb_gadget_giveback_request() because it is allocated in this driver.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
Acked-by: Peter Chen <peter.chen@xxxxxxxxxx>
> ---
> drivers/usb/cdns3/cdns3-gadget.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index d6723d31fc6e2..fd1beb10bba72 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -828,7 +828,11 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
> return;
> }
>
> - if (request->complete) {
> + /*
> + * zlp request is appended by driver, needn't call usb_gadget_giveback_request() to notify
> + * gadget composite driver.
> + */
> + if (request->complete && request->buf != priv_dev->zlp_buf) {
> spin_unlock(&priv_dev->lock);
> usb_gadget_giveback_request(&priv_ep->endpoint,
> request);
> --
> 2.34.1
>
--
Thanks,
Peter Chen
