This is a note to let you know that I've just added the patch titled
drivers: staging: rtl8723bs: Fix locking in _rtw_join_timeout_handler()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-staging-rtl8723bs-fix-locking-in-_rtw_join_t.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 00b5e95c9e77b4ab58a5684ea0167844b1133ba8
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Tue Feb 21 15:53:23 2023 +0100
drivers: staging: rtl8723bs: Fix locking in _rtw_join_timeout_handler()
[ Upstream commit 215792eda008f6a1e7ed9d77fa20d582d22bb114 ]
Commit 041879b12ddb ("drivers: staging: rtl8192bs: Fix deadlock in
rtw_joinbss_event_prehandle()") besides fixing the deadlock also
modified _rtw_join_timeout_handler() to use spin_[un]lock_irq()
instead of spin_[un]lock_bh().
_rtw_join_timeout_handler() calls rtw_do_join() which takes
pmlmepriv->scanned_queue.lock using spin_[un]lock_bh(). This
spin_unlock_bh() call re-enables softirqs which triggers an oops in
kernel/softirq.c: __local_bh_enable_ip() when it calls
lockdep_assert_irqs_enabled():
[ 244.506087] WARNING: CPU: 2 PID: 0 at kernel/softirq.c:376 __local_bh_enable_ip+0xa6/0x100
...
[ 244.509022] Call Trace:
[ 244.509048] <IRQ>
[ 244.509100] _rtw_join_timeout_handler+0x134/0x170 [r8723bs]
[ 244.509468] ? __pfx__rtw_join_timeout_handler+0x10/0x10 [r8723bs]
[ 244.509772] ? __pfx__rtw_join_timeout_handler+0x10/0x10 [r8723bs]
[ 244.510076] call_timer_fn+0x95/0x2a0
[ 244.510200] __run_timers.part.0+0x1da/0x2d0
This oops is causd by the switch to spin_[un]lock_irq() which disables
the IRQs for the entire duration of _rtw_join_timeout_handler().
Disabling the IRQs is not necessary since all code taking this lock
runs from either user contexts or from softirqs, switch back to
spin_[un]lock_bh() to fix this.
Fixes: 041879b12ddb ("drivers: staging: rtl8192bs: Fix deadlock in rtw_joinbss_event_prehandle()")
Cc: Duoming Zhou <duoming@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230221145326.7808-1-hdegoede@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme.c b/drivers/staging/rtl8723bs/core/rtw_mlme.c
index 26c40042d2bed..f85ef7dd61b24 100644
--- a/drivers/staging/rtl8723bs/core/rtw_mlme.c
+++ b/drivers/staging/rtl8723bs/core/rtw_mlme.c
@@ -1547,7 +1547,7 @@ void _rtw_join_timeout_handler(struct timer_list *t)
if (adapter->bDriverStopped || adapter->bSurpriseRemoved)
return;
- spin_lock_irq(&pmlmepriv->lock);
+ spin_lock_bh(&pmlmepriv->lock);
if (rtw_to_roam(adapter) > 0) { /* join timeout caused by roaming */
while (1) {
@@ -1575,7 +1575,7 @@ void _rtw_join_timeout_handler(struct timer_list *t)
}
- spin_unlock_irq(&pmlmepriv->lock);
+ spin_unlock_bh(&pmlmepriv->lock);
}
/*
