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Message-ID: <37f3b74d-2354-66c4-1ebb-3e1cefd2ba19@gmail.com>
Date:   Wed, 23 Nov 2022 22:26:52 +0100
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Subject: Re: [PATCH] staging: rtl8192e: Fix potential use-after-free in
 rtllib_rx_Monitor()
Content-Language: en-US
To:     YueHaibing <yuehaibing@huawei.com>, gregkh@linuxfoundation.org,
        wlanfae@realtek.com, Larry.Finger@lwfinger.net, mikem@ring3k.org
Cc:     linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
References: <20221123081253.22296-1-yuehaibing@huawei.com>
From:   Philipp Hortmann <philipp.g.hortmann@gmail.com>
In-Reply-To: <20221123081253.22296-1-yuehaibing@huawei.com>
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Precedence: bulk

On 11/23/22 09:12, YueHaibing wrote:
> The skb is delivered to netif_rx() in rtllib_monitor_rx(), which may free it,
> after calling this, dereferencing skb may trigger use-after-free.
> Found by Smatch.
> 
> Fixes: 94a799425eee ("From: wlanfae <wlanfae@realtek.com> [PATCH 1/8] rtl8192e: Import new version of driver from realtek")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> ---
>   drivers/staging/rtl8192e/rtllib_rx.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8192e/rtllib_rx.c b/drivers/staging/rtl8192e/rtllib_rx.c
> index 6a0f5bbb99ef..f8965afab767 100644
> --- a/drivers/staging/rtl8192e/rtllib_rx.c
> +++ b/drivers/staging/rtl8192e/rtllib_rx.c
> @@ -1489,9 +1489,9 @@ static int rtllib_rx_Monitor(struct rtllib_device *ieee, struct sk_buff *skb,
>   		hdrlen += 4;
>   	}
>   
> -	rtllib_monitor_rx(ieee, skb, rx_stats, hdrlen);
>   	ieee->stats.rx_packets++;
>   	ieee->stats.rx_bytes += skb->len;
> +	rtllib_monitor_rx(ieee, skb, rx_stats, hdrlen);
>   
>   	return 1;
>   }

I was able to set the driver to Monitor mode but I did not get any 
information from it. I think this happens due to the missing support for 
nl80211. Please give me a hint how to do this.

Thanks for your support.

Bye Philipp