Re: [PATCH] ath9k: hif_usb: fix memory leak of urbs in ath9k_hif_usb_dealloc_tx_urbs()

[Toke Høiland-Jørgensen]

Fedor Pchelkin <pchelkin@xxxxxxxxx> writes:

> Syzkaller reports a long-known leak of urbs in
> ath9k_hif_usb_dealloc_tx_urbs().
>
> The cause of the leak is that usb_get_urb() is called but usb_free_urb()
> (or usb_put_urb()) is not called inside usb_kill_urb() as urb->dev or
> urb->ep fields have not been initialized and usb_kill_urb() returns
> immediately.
>
> The patch removes trying to kill urbs located in hif_dev->tx.tx_buf
> because hif_dev->tx.tx_buf is not supposed to contain urbs which are in
> pending state (the pending urbs are stored in hif_dev->tx.tx_pending).
> The tx.tx_lock is acquired so there should not be any changes in the list.
>
> Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
>
> Fixes: 03fb92a432ea ("ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()")
> Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>

Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx>