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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>
To:     Fedor Pchelkin <pchelkin@ispras.ru>, Kalle Valo <kvalo@kernel.org>
Cc:     Fedor Pchelkin <pchelkin@ispras.ru>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Brooke Basile <brookebasile@gmail.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Alexey Khoroshilov <khoroshilov@ispras.ru>
Subject: Re: [PATCH] ath9k: hif_usb: fix memory leak of urbs in
 ath9k_hif_usb_dealloc_tx_urbs()
In-Reply-To: <20220725151359.283704-1-pchelkin@ispras.ru>
References: <20220725151359.283704-1-pchelkin@ispras.ru>
Date:   Fri, 07 Oct 2022 20:22:11 +0200
Message-ID: <871qrjtrxo.fsf@toke.dk>
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Fedor Pchelkin <pchelkin@ispras.ru> 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@ispras.ru>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>

Acked-by: Toke H=C3=B8iland-J=C3=B8rgensen <toke@toke.dk>