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From bcc5e2dcf09089b337b76fc1a589f6ff95ca19ac Mon Sep 17 00:00:00 2001
From: Dan Carpenter <error27@gmail.com>
Date: Wed, 23 Nov 2022 09:43:14 +0300
Subject: [PATCH] staging: rtl8192u: Fix use after free in ieee80211_rx()
Git-commit: bcc5e2dcf09089b337b76fc1a589f6ff95ca19ac
Patch-mainline: v6.2-rc1
References: git-fixes

We cannot dereference the "skb" pointer after calling
ieee80211_monitor_rx(), because it is a use after free.

Fixes: 8fc8598e61f6 ("Staging: Added Realtek rtl8192u driver to staging")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y33BArx3k/aw6yv/@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
index f142d0986990..5c73e3f8541a 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
@@ -951,9 +951,11 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb,
 #endif
 
 	if (ieee->iw_mode == IW_MODE_MONITOR) {
+		unsigned int len = skb->len;
+
 		ieee80211_monitor_rx(ieee, skb, rx_stats);
 		stats->rx_packets++;
-		stats->rx_bytes += skb->len;
+		stats->rx_bytes += len;
 		return 1;
 	}
 
-- 
2.35.3