[PATCH] staging: rtl8723bs: protect sleepq_len access by sleep_q.lock

From: Fabio Aiuto
Date: Mon Sep 13 2021 - 09:08:22 EST


protect sleepq_len access by sleep_q.lock and move
pxmitpriv->lock after sleep_q.lock release.

This fixes and completes a lockdep warning silencing
done in a prevoius commit where accesses to sleep_q
related fields were protected by sleep_q.lock instead
of pxmitpriv->lock.

Note that sleep_q.lock is already taken inside
rtw_free_xmitframe_queue so we just wrap sleepq_len
access.

Moved pxmitpriv->lock after sleep_q.lock release to
avoid locks nesting.

Fixes: 78a1614a81f0 ("staging: rtl8723bs: remove possible deadlock when disconnect")
Reported-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Tested-by: Fabio Aiuto <fabioaiuto83@xxxxxxxxx>
Signed-off-by: Fabio Aiuto <fabioaiuto83@xxxxxxxxx>
---
drivers/staging/rtl8723bs/core/rtw_sta_mgt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c b/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c
index bf090f3b1db6..c98918e02afe 100644
--- a/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c
+++ b/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c
@@ -294,10 +294,12 @@ u32 rtw_free_stainfo(struct adapter *padapter, struct sta_info *psta)

/* list_del_init(&psta->wakeup_list); */

- spin_lock_bh(&pxmitpriv->lock);
-
rtw_free_xmitframe_queue(pxmitpriv, &psta->sleep_q);
+ spin_lock_bh(&psta->sleep_q.lock);
psta->sleepq_len = 0;
+ spin_unlock_bh(&psta->sleep_q.lock);
+
+ spin_lock_bh(&pxmitpriv->lock);

/* vo */
/* spin_lock_bh(&(pxmitpriv->vo_pending.lock)); */
--
2.20.1