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drivers: staging: rtl8723bs: Fix locking in _rtw_join_timeout_handler()

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[ 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@zju.edu.cn>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230221145326.7808-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hans de Goede
2023-02-21 15:53:23 +01:00
committed by Greg Kroah-Hartman
parent 1ffb2ca650
commit 209850f177
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/staging/rtl8723bs/core/rtw_mlme.c
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@@ -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);
}
/*