On Tue, Mar 30, 2021 at 10:36:52PM +0300, Pavel Skripkin wrote: > Hi! > > I did some debugging on this > https://syzkaller.appspot.com/bug?id=3ea507fb3c47426497b52bd82b8ef0dd5b6cc7ee > and, I believe, I recognized the problem. The problem appears in case of > ath9k_htc_hw_init() fail. In case of this fail all tx_buf->urb krefs will be > initialized to 1, but in free function: > > static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev) > > .... > > static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev) > { > ... > list_for_each_entry_safe(tx_buf, tx_buf_tmp, > &hif_dev->tx.tx_buf, list) { > usb_get_urb(tx_buf->urb); > ... > usb_free_urb(tx_buf->urb); > ... > } > > Krefs are incremented and then decremented, that means urbs won't be freed. > I found your patch and I can't properly understand why You added > usb_get_urb(tx_buf->urb). > Can You explain please, I believe this will help me or somebody to fix this > ussue :)
I think almost everyone who has looked into this has given up due to the mess of twisty-passages here with almost no real-world benefits for unwinding them :) Good luck! greg k-h
