WARNING in hrtimer_forward

WARNING in hrtimer_forward

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    12450081 libbpf: Fix native endian assumption when parsing..
git tree:       bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=10bf85c5900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5ac0d21536db480b
dashboard link: https://syzkaller.appspot.com/bug?extid=ca740b95a16399ceb9a5
compiler:       gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ca740b95a16399ceb9a5@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 9082 at kernel/time/hrtimer.c:932 hrtimer_forward+0x1e3/0x260 kernel/time/hrtimer.c:932
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9082 Comm: syz-executor.4 Not tainted 5.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 __warn.cold+0x20/0x4b kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:hrtimer_forward+0x1e3/0x260 kernel/time/hrtimer.c:932
Code: e5 4d 0f 4e ec e8 1d 25 10 00 4c 89 6b 20 e8 14 25 10 00 4c 89 f0 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 fd 24 10 00 <0f> 0b 45 31 f6 eb dd e8 f1 24 10 00 4c 89 e0 48 8b 3c 24 48 99 48
RSP: 0018:ffffc90000da8d90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88805cb74b78 RCX: ffffffff816606b8
RDX: ffff88805a4aa380 RSI: ffffffff81660803 RDI: 0000000000000001
RBP: 00000000061a8000 R08: 0000000000000001 R09: ffff88805a4aac60
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000002b545ee359 R14: 0000000000000001 R15: dffffc0000000000
 mac80211_hwsim_beacon+0x159/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1726
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1588
 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1605
 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x235/0x280 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199
Code: c0 b8 6b fc 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d c6 df d5 01 00 74 25 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 ab 59 2a f9 65 8b 05 74 72 db 77 85 c0 74 02 5d
RSP: 0018:ffffc9000767f550 EFLAGS: 00000286
RAX: 1ffffffff13f8d77 RBX: ffff88805a4aa380 RCX: 0000000000000006
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8880ae535e00 R08: 0000000000000001 R09: ffffffff8d0b69ef
R10: fffffbfff1a16d3d R11: 0000000000000000 R12: ffff8880ae535e00
R13: ffff888087046300 R14: 0000000000000000 R15: 0000000000000001
 finish_lock_switch kernel/sched/core.c:3517 [inline]
 finish_task_switch+0x150/0x790 kernel/sched/core.c:3617
 context_switch kernel/sched/core.c:3781 [inline]
 __schedule+0xed1/0x2280 kernel/sched/core.c:4527
 preempt_schedule_irq+0xbf/0x1b0 kernel/sched/core.c:4785
 irqentry_exit_cond_resched kernel/entry/common.c:333 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:325 [inline]
 irqentry_exit+0x65/0x90 kernel/entry/common.c:363
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:__sanitizer_cov_trace_pc+0x42/0x60 kernel/kcov.c:202
Code: 24 74 0f f6 c4 01 74 35 8b 82 2c 14 00 00 85 c0 74 2b 8b 82 08 14 00 00 83 f8 02 75 20 48 8b 8a 10 14 00 00 8b 92 0c 14 00 00 <48> 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 c3 66 2e
RSP: 0018:ffffc9000767f780 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffc9000767f918 RCX: ffffc90011138000
RDX: 0000000000040000 RSI: ffffffff83889163 RDI: ffffc9000767f938
RBP: ffff88808c3a5f00 R08: 0000000000000000 R09: ffffffff8a68da47
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88808ea8f818 R14: ffff88808c3a5f18 R15: 0000000000000002
 tomoyo_same_path_number_acl+0x63/0x2c0 security/tomoyo/file.c:639
 tomoyo_update_domain+0x34c/0x850 security/tomoyo/domain.c:128
 tomoyo_update_path_number_acl security/tomoyo/file.c:691 [inline]
 tomoyo_write_file+0x68b/0x7f0 security/tomoyo/file.c:1034
 tomoyo_write_domain2+0x116/0x1d0 security/tomoyo/common.c:1152
 tomoyo_add_entry security/tomoyo/common.c:2042 [inline]
 tomoyo_supervisor+0xbc4/0xef0 security/tomoyo/common.c:2103
 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
 tomoyo_path_number_perm+0x419/0x590 security/tomoyo/file.c:734
 security_file_ioctl+0x50/0xb0 security/security.c:1480
 __do_sys_ioctl fs/ioctl.c:747 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: 3d b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f720959bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000000153c0 RCX: 000000000045e179
RDX: 0000000020000000 RSI: 0000000000008914 RDI: 0000000000000006
RBP: 000000000118d028 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cff4
R13: 00007ffdf66d8fdf R14: 00007f720959c9c0 R15: 000000000118cff4
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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Re: WARNING in hrtimer_forward

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    ba5f4cfe bpf: Add comment to document BTF type PTR_TO_BTF_..
git tree:       bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13f316e5900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d44e1360b76d34dc
dashboard link: https://syzkaller.appspot.com/bug?extid=ca740b95a16399ceb9a5
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1148fe4b900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f5218d900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ca740b95a16399ceb9a5@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6901 at kernel/time/hrtimer.c:932 hrtimer_forward+0x1e3/0x260 kernel/time/hrtimer.c:932
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 6901 Comm: kworker/u4:1 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: phy4 ieee80211_iface_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 __warn.cold+0x20/0x4b kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:hrtimer_forward+0x1e3/0x260 kernel/time/hrtimer.c:932
Code: e5 4d 0f 4e ec e8 ad 24 10 00 4c 89 6b 20 e8 a4 24 10 00 4c 89 f0 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 8d 24 10 00 <0f> 0b 45 31 f6 eb dd e8 81 24 10 00 4c 89 e0 48 8b 3c 24 48 99 48
RSP: 0018:ffffc90000007d90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88808ded4b78 RCX: ffffffff81666168
RDX: ffff8880942f0200 RSI: ffffffff816662b3 RDI: 0000000000000001
RBP: 00000000061a8000 R08: 0000000000000001 R09: ffff8880942f0b00
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 000000a6d77ff62e R14: 0000000000000001 R15: dffffc0000000000
 mac80211_hwsim_beacon+0x159/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1726
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1588
 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1605
 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x235/0x280 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline]
RIP: 0010:lock_acquire+0x27b/0xaf0 kernel/locking/lockdep.c:5032
Code: ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 1d 07 00 00 48 83 3d d8 41 a0 08 00 0f 84 73 05 00 00 4c 89 ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 08 48 c7
RSP: 0018:ffffc90000e37c18 EFLAGS: 00000286
RAX: 1ffffffff13f8d7d RBX: ffff8880942f0200 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286
RBP: ffffc90000e37da8 R08: 0000000000000000 R09: ffffffff8d108aa7
R10: fffffbfff1a21154 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000286
 process_one_work+0x8bb/0x1670 kernel/workqueue.c:2245
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Kernel Offset: disabled
Rebooting in 86400 seconds..

Re: WARNING in hrtimer_forward

[syzbot]

syzbot has bisected this issue to:

commit 0e7bbcc104baaade4f64205e9706b7d43c46db7d
Author: Julian Anastasov <ja@ssi.bg>
Date:   Wed Jul 27 06:56:50 2016 +0000

    neigh: allow admin to set NUD_STALE

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1661d187900000
start commit:   ba5f4cfe bpf: Add comment to document BTF type PTR_TO_BTF_..
git tree:       bpf-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=1561d187900000
console output: https://syzkaller.appspot.com/x/log.txt?x=1161d187900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d44e1360b76d34dc
dashboard link: https://syzkaller.appspot.com/bug?extid=ca740b95a16399ceb9a5
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1148fe4b900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f5218d900000

Reported-by: syzbot+ca740b95a16399ceb9a5@syzkaller.appspotmail.com
Fixes: 0e7bbcc104ba ("neigh: allow admin to set NUD_STALE")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: WARNING in hrtimer_forward

[Thomas Gleixner]

On Sun, Sep 27 2020 at 16:04, Hillf Danton wrote:
> Sat, 26 Sep 2020 17:38:16 -0700
>
> Dunno if it's down to memory barrier.
>
> --- a/kernel/time/hrtimer.c
> +++ b/kernel/time/hrtimer.c
> @@ -929,7 +929,7 @@ u64 hrtimer_forward(struct hrtimer *time
>  	if (delta < 0)
>  		return 0;
>  
> -	if (WARN_ON(timer->state & HRTIMER_STATE_ENQUEUED))
> +	if (WARN_ON(hrtimer_is_queued(timer)))
>  		return 0;

The point of that exercise is?

Re: WARNING in hrtimer_forward

[Thomas Gleixner]

On Sun, Sep 27 2020 at 07:29, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit 0e7bbcc104baaade4f64205e9706b7d43c46db7d
> Author: Julian Anastasov <ja@ssi.bg>
> Date:   Wed Jul 27 06:56:50 2016 +0000
>
>     neigh: allow admin to set NUD_STALE
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1661d187900000
> start commit:   ba5f4cfe bpf: Add comment to document BTF type PTR_TO_BTF_..
> git tree:       bpf-next
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=1561d187900000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1161d187900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d44e1360b76d34dc
> dashboard link: https://syzkaller.appspot.com/bug?extid=ca740b95a16399ceb9a5
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1148fe4b900000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f5218d900000
>
> Reported-by: syzbot+ca740b95a16399ceb9a5@syzkaller.appspotmail.com
> Fixes: 0e7bbcc104ba ("neigh: allow admin to set NUD_STALE")

That bisect does not make any sense and reverting the commit on top of
next does not help either.

What happens is:

            fail-16132   [029] ....   933.714866: sys_enter: NR 16 (3, 8b28, 20000000, 0, 0, 0)
          <idle>-0       [001] d.s2   933.715768: hrtimer_cancel: hrtimer=00000000fe9fe1b9
          <idle>-0       [001] ..s1   933.715771: hrtimer_expire_entry: hrtimer=00000000fe9fe1b9 function=mac80211_hwsim_beacon now=933716506319
            fail-16132   [029] d..1   933.715794: hrtimer_start: hrtimer=00000000fe9fe1b9 function=mac80211_hwsim_beacon expires=933818720770 softexpires=933818720770 mode=REL|SOFT
          <idle>-0       [001] ..s1   933.715812: hrtimer_forward: hrtimer=00000000fe9fe1b9

So the timer was armed at some point and then the expiry which does the
forward races with the ioctl which starts the timer. Lack of
serialization or such ...

Thanks,

        tglx

Re: WARNING in hrtimer_forward

[Thomas Gleixner]

On Tue, Sep 29 2020 at 01:11, Hillf Danton wrote:
> On Mon, 28 Sep 2020 18:13:42 +0200 Thomas Gleixner wrote:
>> So the timer was armed at some point and then the expiry which does the
>> forward races with the ioctl which starts the timer. Lack of
>> serialization or such ...
>
> To make syzbot happy, s/hrtimer_is_queued/hrtimer_active/ can close
> that race but this warning looks benign.

Why only make sysbot happy? It's clearly an issue and the warning is not
benign simply because forwarding a queued timer is an absolute NONO.
timers (both timer_list and hrtimer) need external synchronization.

> --- a/drivers/net/wireless/mac80211_hwsim.c
> +++ b/drivers/net/wireless/mac80211_hwsim.c
> @@ -1698,7 +1698,7 @@ static int mac80211_hwsim_config(struct
>  
>  	if (!data->started || !data->beacon_int)
>  		hrtimer_cancel(&data->beacon_timer);
> -	else if (!hrtimer_is_queued(&data->beacon_timer)) {
> +	else if (!hrtimer_active(&data->beacon_timer)) {
>  		u64 tsf = mac80211_hwsim_get_tsf(hw, NULL);
>  		u32 bcn_int = data->beacon_int;
>  		u64 until_tbtt = bcn_int - do_div(tsf, bcn_int);
> @@ -1768,7 +1768,7 @@ static void mac80211_hwsim_bss_info_chan
>  			  info->enable_beacon, info->beacon_int);
>  		vp->bcn_en = info->enable_beacon;
>  		if (data->started &&
> -		    !hrtimer_is_queued(&data->beacon_timer) &&
> +		    !hrtimer_active(&data->beacon_timer) &&
>  		    info->enable_beacon) {
>  			u64 tsf, until_tbtt;
>  			u32 bcn_int;

Looks about right.

Thanks,

        tglx


   

Re: WARNING in hrtimer_forward

[Dmitry Vyukov]

On Mon, Sep 28, 2020 at 8:36 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> On Tue, Sep 29 2020 at 01:11, Hillf Danton wrote:
> > On Mon, 28 Sep 2020 18:13:42 +0200 Thomas Gleixner wrote:
> >> So the timer was armed at some point and then the expiry which does the
> >> forward races with the ioctl which starts the timer. Lack of
> >> serialization or such ...
> >
> > To make syzbot happy, s/hrtimer_is_queued/hrtimer_active/ can close
> > that race but this warning looks benign.
>
> Why only make sysbot happy? It's clearly an issue and the warning is not
> benign simply because forwarding a queued timer is an absolute NONO.
> timers (both timer_list and hrtimer) need external synchronization.

Oh, Thomas, it's so nice to hear this interpretation of things among
all the cases where people only fixing tools and making them happy :)
Don't make my tools happy! They don't need that! :)

Re: [syzbot] WARNING in hrtimer_forward

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 313bbd1990b6ddfdaa7da098d0c56b098a833572
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Wed Sep 15 09:29:37 2021 +0000

    mac80211-hwsim: fix late beacon hrtimer handling

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=108b5712b00000
start commit:   ba5f4cfeac77 bpf: Add comment to document BTF type PTR_TO_..
git tree:       bpf-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=d44e1360b76d34dc
dashboard link: https://syzkaller.appspot.com/bug?extid=ca740b95a16399ceb9a5
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1148fe4b900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f5218d900000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: mac80211-hwsim: fix late beacon hrtimer handling

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] WARNING in hrtimer_forward

[Dmitry Vyukov]

On Wed, 3 Nov 2021 at 10:21, syzbot
<syzbot+ca740b95a16399ceb9a5@syzkaller.appspotmail.com> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit 313bbd1990b6ddfdaa7da098d0c56b098a833572
> Author: Johannes Berg <johannes.berg@intel.com>
> Date:   Wed Sep 15 09:29:37 2021 +0000
>
>     mac80211-hwsim: fix late beacon hrtimer handling
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=108b5712b00000
> start commit:   ba5f4cfeac77 bpf: Add comment to document BTF type PTR_TO_..
> git tree:       bpf-next
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d44e1360b76d34dc
> dashboard link: https://syzkaller.appspot.com/bug?extid=ca740b95a16399ceb9a5
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1148fe4b900000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f5218d900000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: mac80211-hwsim: fix late beacon hrtimer handling
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Looks legit:

#syz fix: mac80211-hwsim: fix late beacon hrtimer handling