| Description | In the Linux kernel, the following vulnerability has been resolved:
usb: cdns3: fix memory double free when handle zero packet
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. |