From ec89032cd148f8805c5adf5d38f1f382036f5a5c Mon Sep 17 00:00:00 2001
From: Reto Schneider <code@reto-schneider.ch>
Date: Mon, 22 Jun 2020 15:21:11 +0200
Subject: [PATCH] rtlwifi: rtl8192cu: Fix deadlock
Git-commit: ec89032cd148f8805c5adf5d38f1f382036f5a5c
Patch-mainline: v5.9-rc1
References: jsc#SLE-13430
Prevent code from calling itself indirectly, causing the driver to hang
and consume 100% CPU.
Without this fix, the following script can bring down a single CPU
System:
```
while true; do
rmmod rtl8192cu
modprobe rtl8192cu
done
```
Signed-off-by: Reto Schneider <code@reto-schneider.ch>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200622132113.14508-2-code@reto-schneider.ch
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/wireless/realtek/rtlwifi/usb.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c
index c66c6dc00378..d3bbfc0171f6 100644
--- a/drivers/net/wireless/realtek/rtlwifi/usb.c
+++ b/drivers/net/wireless/realtek/rtlwifi/usb.c
@@ -680,8 +680,10 @@ static void _rtl_usb_cleanup_rx(struct ieee80211_hw *hw)
tasklet_kill(&rtlusb->rx_work_tasklet);
cancel_work_sync(&rtlpriv->works.lps_change_work);
- flush_workqueue(rtlpriv->works.rtl_wq);
- destroy_workqueue(rtlpriv->works.rtl_wq);
+ if (rtlpriv->works.rtl_wq) {
+ destroy_workqueue(rtlpriv->works.rtl_wq);
+ rtlpriv->works.rtl_wq = NULL;
+ }
skb_queue_purge(&rtlusb->rx_queue);
--
2.16.4