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 spinunlock(&privdev->lock); 831 usbgadgetgivebackrequest(&privep->endpoint, 832 request); 833 spinlock(&privdev->lock); 834 } 835 836 if (request->buf == privdev->zlpbuf) 837 cdns3gadgetepfreerequest(&privep->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, usbgadgetgivebackrequest() will free this requestion. 836 condition is true, so cdns3gadgetepfreerequest() free this request again. Log: [ 1920.140696][ T150] BUG: KFENCE: use-after-free read in cdns3gadgetgiveback+0x134/0x2c0 [cdns3] [ 1920.140696][ T150] [ 1920.151837][ T150] Use-after-free read at 0x000000003d1cd10b (in kfence-#36): [ 1920.159082][ T150] cdns3gadgetgiveback+0x134/0x2c0 [cdns3] [ 1920.164988][ T150] cdns3transfercompleted+0x438/0x5f8 [cdns3] Add check at line 829, skip call usbgadgetgivebackrequest() if it is additional zero length packet request. Needn't call usbgadgetgivebackrequest() because it is allocated in this driver.