From 215792eda008f6a1e7ed9d77fa20d582d22bb114 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 21 Feb 2023 15:53:23 +0100 Subject: [PATCH] drivers: staging: rtl8723bs: Fix locking in _rtw_join_timeout_handler() 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] [ 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 Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20230221145326.7808-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8723bs/core/rtw_mlme.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme.c b/drivers/staging/rtl8723bs/core/rtw_mlme.c index c6fd6cf741ef..ea2a6566e51b 100644 --- a/drivers/staging/rtl8723bs/core/rtw_mlme.c +++ b/drivers/staging/rtl8723bs/core/rtw_mlme.c @@ -1549,7 +1549,7 @@ 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) { @@ -1577,7 +1577,7 @@ void _rtw_join_timeout_handler(struct timer_list *t) } - spin_unlock_irq(&pmlmepriv->lock); + spin_unlock_bh(&pmlmepriv->lock); } /*