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SubjectRe: [PATCH v2] ath9k_htc: Add a missing spin_lock_init()
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Rajat Asthana <rajatasthana4@gmail.com> wrote:

> Syzkaller reported a lockdep warning on non-initialized spinlock:
>
> INFO: trying to register non-static key.
> The code is fine but needs lockdep annotation, or maybe
> you didn't initialize this object before use?
> turning off the locking correctness validator.
> CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:79 [inline]
> dump_stack+0x143/0x1db lib/dump_stack.c:120
> assign_lock_key kernel/locking/lockdep.c:937 [inline]
> register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
> __lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
> lock_acquire kernel/locking/lockdep.c:5512 [inline]
> lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
> _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
> spin_lock_bh include/linux/spinlock.h:359 [inline]
> ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
> tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
> __do_softirq+0x1b0/0x944 kernel/softirq.c:559
> run_ksoftirqd kernel/softirq.c:921 [inline]
> run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
> smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
> kthread+0x38c/0x460 kernel/kthread.c:313
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
>
> We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
> event is WMI_TXSTATUS_EVENTID. So, add a spin_lock_init() in
> ath9k_init_wmi().
>
> Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

The lock is already initialised in ath9k_init_priv(), so now the same lock is
initialised twice. ath9k_init_wmi() is called before ath9k_init_priv(), so it
looks like we have a race somewhere.

Patch set to Changes Requested.

--
https://patchwork.kernel.org/project/linux-wireless/patch/20210728192533.18727-1-rajatasthana4@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

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