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From:   YueHaibing <yuehaibing@huawei.com>
To:     <gregkh@linuxfoundation.org>, <wlanfae@realtek.com>,
        <Larry.Finger@lwfinger.net>, <mikem@ring3k.org>
CC:     <linux-staging@lists.linux.dev>, <linux-kernel@vger.kernel.org>,
        YueHaibing <yuehaibing@huawei.com>
Subject: [PATCH] staging: rtl8192e: Fix potential use-after-free in rtllib_rx_Monitor()
Date:   Wed, 23 Nov 2022 16:12:53 +0800
Message-ID: <20221123081253.22296-1-yuehaibing@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

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;
 }
-- 
2.17.1