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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>,
        Zekun Shen <bruceshenzk@gmail.com>,
        Joe Perches <joe@perches.com>,
        "John W. Linville" <linville@tuxdriver.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Alexey Khoroshilov <khoroshilov@ispras.ru>,
        lvc-project@linuxtesting.org,
        syzbot+e9632e3eb038d93d6bc6@syzkaller.appspotmail.com
Subject: Re: [PATCH v3] wifi: ath9k: hif_usb: clean up skbs if
 ath9k_hif_usb_rx_stream() fails
In-Reply-To: <20230104123615.51511-1-pchelkin@ispras.ru>
References: <20230104123615.51511-1-pchelkin@ispras.ru>
Date:   Wed, 04 Jan 2023 15:50:26 +0100
Message-ID: <87tu161hhp.fsf@toke.dk>
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Fedor Pchelkin <pchelkin@ispras.ru> writes:

> Syzkaller detected a memory leak of skbs in ath9k_hif_usb_rx_stream().
> While processing skbs in ath9k_hif_usb_rx_stream(), the already allocated
> skbs in skb_pool are not freed if ath9k_hif_usb_rx_stream() fails. If we
> have an incorrect pkt_len or pkt_tag, the input skb is considered invalid
> and dropped. All the associated packets already in skb_pool should be
> dropped and freed. Added a comment describing this issue.
>
> The patch also makes remain_skb NULL after being processed so that it
> cannot be referenced after potential free. The initialization of hif_dev
> fields which are associated with remain_skb (rx_remain_len,
> rx_transfer_len and rx_pad_len) is moved after a new remain_skb is
> allocated.=20
>
> Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
>
> Fixes: 6ce708f54cc8 ("ath9k: Fix out-of-bound memcpy in ath9k_hif_usb_rx_=
stream")
> Fixes: 44b23b488d44 ("ath9k: hif_usb: Reduce indent 1 column")
> Reported-by: syzbot+e9632e3eb038d93d6bc6@syzkaller.appspotmail.com
> 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>