staging: rtl8192e: Fix potential use-after-free in rtllib_rx_Monitor()

[ Upstream commit a76ba50e94ce779473ecd4a5f98e892ad52d73b2 ]

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: 08b1c91be271 ("From: wlanfae <wlanfae@realtek.com> [PATCH 1/8] rtl8192e: Import new version of driver from realtek")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20221123081253.22296-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/staging/rtl8192e/rtllib_rx.c b/drivers/staging/rtl8192e/rtllib_rx.c
index 46d75e925ee9b780e07fddf53f29c1c5b6e76a2e..f710eb2a95f3aff77ac3b9be3b245607d0c33142 100644 (file)
--- 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;
 }