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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>
Linux kernel
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