syzbot

vkms_vblank_simulate: vblank timer overrun
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=88ec/1/0x4000000000000000 softirq=122718/122718 fqs=4
rcu: 	(detected by 0, t=10502 jiffies, g=185497, q=144 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 26220 Comm: syz-executor.0 Not tainted 6.9.0-rc6-syzkaller-00234-g7367539ad4b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:206
Code: 8b 3d 0c f1 3e 0c 48 89 de 5b e9 73 2b 59 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 c0 d3 03 00 65 8b 15 f0 c2 6d 7e f7 c2 00 01 ff 00
RSP: 0018:ffffc90000a08b98 EFLAGS: 00000046
RAX: ffffffff89526544 RBX: 0000000000000001 RCX: ffffffff89526511
RDX: ffff888016ee5a00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000a08c80 R08: ffffffff8952653a R09: 1ffff1100305e82b
R10: dffffc0000000000 R11: ffffed100305e82c R12: ffff8880182f4000
R13: dffffc0000000000 R14: 1ffff92000141178 R15: ffff8880182f4300
FS:  00007f6c95fcb6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020cab000 CR3: 000000005de48000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __netif_schedule+0xc4/0x310 net/core/dev.c:3086
 advance_sched+0xaa9/0xca0 net/sched/sch_taprio.c:986
 __run_hrtimer kernel/time/hrtimer.c:1692 [inline]
 __hrtimer_run_queues+0x5a7/0xd50 kernel/time/hrtimer.c:1756
 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
 __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758
Code: 2b 00 74 08 4c 89 f7 e8 6a 2c 88 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90016a978e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92002d52f28 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8bcaca20 RDI: ffffffff8c1f7ee0
RBP: ffffc90016a97a38 R08: ffffffff92f35537 R09: 1ffffffff25e6aa6
R10: dffffc0000000000 R11: fffffbfff25e6aa7 R12: 1ffff92002d52f24
R13: dffffc0000000000 R14: ffffc90016a97940 R15: 0000000000000246
 __might_fault+0xc6/0x120 mm/memory.c:6220
 do_recvmmsg+0x5e1/0xae0 net/socket.c:2945
 __sys_recvmmsg net/socket.c:3018 [inline]
 __do_sys_recvmmsg net/socket.c:3041 [inline]
 __se_sys_recvmmsg net/socket.c:3034 [inline]
 __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6c9527dca9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6c95fcb0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f6c953ac050 RCX: 00007f6c9527dca9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007f6c952c947e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f6c953ac050 R15: 00007fff3da83e48
 </TASK>
rcu: rcu_preempt kthread starved for 10492 jiffies! g185497 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:25400 pid:16    tgid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582
 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 21512 Comm: kworker/u8:8 Not tainted 6.9.0-rc6-syzkaller-00234-g7367539ad4b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855
Code: 89 e6 83 e6 01 31 ff e8 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 0b 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 a4 d6 0b 00 eb e4 44
RSP: 0018:ffffc9000ce876e0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110172a8869 RCX: ffff888034998000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000ce878e0 R08: ffffffff818a39eb R09: 1ffffffff25e6aa0
R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: dffffc0000000000
R13: ffff8880b9544348 R14: ffff8880b943f7c0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055559293e938 CR3: 000000000e134000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2086 [inline]
 text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296
 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205
 static_key_enable+0x1a/0x20 kernel/jump_label.c:218
 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>