syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=6dd4/1/0x4000000000000000 softirq=13590/13590 fqs=2
rcu: 	(detected by 0, t=10502 jiffies, g=14589, q=228 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_freezable_power_ sync_hw_clock
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:33 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline]
RIP: 0010:lock_acquire+0x151/0x420 kernel/locking/lockdep.c:5750
Code: 3e 00 0f 85 17 01 00 00 43 c6 44 3c 08 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 <43> c6 44 3c 08 f8 fa 48 c7 c7 c0 d8 ca 8a e8 dc 40 20 09 65 ff 05
RSP: 0018:ffffc900001f0b40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 80639572b282ba00
RDX: 0000000000000000 RSI: ffffffff8b1c9c00 RDI: ffffffff8b1c9bc0
RBP: ffffc900001f0c50 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: 1ffff9200003e174
R13: ffff88802ee73300 R14: 0000000000000046 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000012c0 CR3: 000000002d153000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 advance_sched+0xb5/0xc20 net/sched/sch_taprio.c:940
 __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
 __hrtimer_run_queues+0x520/0xc40 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1880
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90000a2faa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 80639572b282ba00
RDX: ffffffff90d3d420 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9c20
RBP: ffffc90000a2fba8 R08: dffffc0000000000 R09: 0000000000000002
R10: ffffffff93a6bb44 R11: fffffbfff21a2c09 R12: 1ffff92000145f60
R13: ffff888017c72138 R14: 0000000000000246 R15: dffffc0000000000
 process_one_work kernel/workqueue.c:2628 [inline]
 process_scheduled_works+0x985/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g14589 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:27656 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 5970 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfe/0x1140 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 4b f7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 86 f3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 6a f3
RSP: 0018:ffffc90003287740 EFLAGS: 00000293
RAX: ffffffff817c3826 RBX: 1ffff110171e827d RCX: ffff88807a5b1e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900032878c0 R08: ffffffff911cd537 R09: 1ffffffff2239aa6
R10: dffffc0000000000 R11: fffffbfff2239aa7 R12: ffff8880b8f413e8
R13: dffffc0000000000 R14: ffff8880b8e3d1c8 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561fc5164048 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:990 [inline]
 flush_tlb_mm_range+0x424/0x6a0 arch/x86/mm/tlb.c:1078
 tlb_flush arch/x86/include/asm/tlb.h:20 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:474 [inline]
 tlb_flush_mmu+0x1bd/0x510 mm/mmu_gather.c:300
 tlb_finish_mmu+0xf9/0x220 mm/mmu_gather.c:425
 exit_mmap+0x428/0xb90 mm/mmap.c:3315
 __mmput+0x118/0x3c0 kernel/fork.c:1357
 exit_mm+0x24a/0x350 kernel/exit.c:570
 do_exit+0x8dd/0x2460 kernel/exit.c:871
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1026
 __do_sys_exit_group kernel/exit.c:1037 [inline]
 __se_sys_exit_group kernel/exit.c:1035 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f46bab9ce59
Code: Unable to access opcode bytes at 0x7f46bab9ce2f.
RSP: 002b:00007ffdfb4a7ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f46bab9ce59
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f46bade73e0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f46bade73e0 R14: 0000000000000003 R15: 00007ffdfb4a7fb0
 </TASK>