On 02/02/2024 17:42, 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> Reviewed-by: Roger Quadros <rogerq@xxxxxxxxxx>