------------[ cut here ]------------
cpu_t != t
WARNING: arch/x86/kernel/cpu/mce/core.c:1770 at mce_timer_fn+0x289/0x2e0 arch/x86/kernel/cpu/mce/core.c:1770, CPU#2: syz.5.71/6645
Modules linked in:
CPU: 2 UID: 0 PID: 6645 Comm: syz.5.71 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:mce_timer_fn+0x289/0x2e0 arch/x86/kernel/cpu/mce/core.c:1770
Code: 58 00 4d 01 e4 4d 39 ec 4d 0f 47 e5 31 ff 4c 89 e6 e8 1b 47 58 00 4d 85 e4 0f 84 20 ff ff ff e9 f7 fe ff ff e8 68 4c 58 00 90 <0f> 0b 90 e9 cf fd ff ff 4c 89 f6 48 c7 c7 00 ce 9f 8e e8 c0 2c 86
RSP: 0000:ffffc90000538c30 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88802b423440 RCX: ffffffff81f4c30d
RDX: ffff8880471c8000 RSI: ffffffff81b15ff8 RDI: ffffffff8e46c930
RBP: ffff88802b323440 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: 1ffff920000a718e R14: ffffffff81b15d70 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888096de3000(0063) knlGS:00000000f5466b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f51b3550 CR3: 0000000026e95000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 call_timer_fn+0x19a/0x610 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb00 kernel/time/timer.c:2374
 __run_timer_base kernel/time/timer.c:2386 [inline]
 __run_timer_base kernel/time/timer.c:2378 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2395
 run_timer_softirq+0x10/0x50 kernel/time/timer.c:2403
 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 76 07 2a f6 48 89 df e8 fe 56 2a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 d5 66 19 f6 65 8b 05 4e 77 a8 08 85 c0 74 16 5b
RSP: 0000:ffffc90002e27928 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffe8ffac110c40 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8e1a87c3 RDI: ffffffff8c400a80
RBP: 0000000000000282 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888022479800
R13: dffffc0000000000 R14: 0000000000000108 R15: 0000000000000001
 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
 free_cpu_cached_iovas+0x10e/0x190 drivers/iommu/iova.c:918
 iova_cpuhp_dead+0x30/0x40 drivers/iommu/iova.c:949
 cpuhp_invoke_callback+0x513/0x9a0 kernel/cpu.c:216
 __cpuhp_invoke_callback_range+0x158/0x1d0 kernel/cpu.c:972
 cpuhp_invoke_callback_range kernel/cpu.c:996 [inline]
 cpuhp_down_callbacks kernel/cpu.c:1386 [inline]
 _cpu_down+0x523/0x1020 kernel/cpu.c:1457
 cpu_down_maps_locked kernel/cpu.c:1483 [inline]
 cpu_down kernel/cpu.c:1491 [inline]
 cpu_device_down+0x82/0xc0 kernel/cpu.c:1508
 device_offline drivers/base/core.c:4279 [inline]
 device_offline+0x2f4/0x400 drivers/base/core.c:4263
 online_store+0xd1/0x180 drivers/base/core.c:2879
 dev_attr_store+0x58/0x80 drivers/base/core.c:2505
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fa8fec
Code: Unable to access opcode bytes at 0xf7fa8fc2.
RSP: 002b:00000000f546650c EFLAGS: 00000292 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000180
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	f5                   	cmc
   1:	53                   	push   %rbx
   2:	48 8b 74 24 10       	mov    0x10(%rsp),%rsi
   7:	48 89 fb             	mov    %rdi,%rbx
   a:	48 83 c7 18          	add    $0x18,%rdi
   e:	e8 76 07 2a f6       	call   0xf62a0789
  13:	48 89 df             	mov    %rbx,%rdi
  16:	e8 fe 56 2a f6       	call   0xf62a5719
  1b:	f7 c5 00 02 00 00    	test   $0x200,%ebp
  21:	75 23                	jne    0x46
  23:	9c                   	pushf
  24:	58                   	pop    %rax
  25:	f6 c4 02             	test   $0x2,%ah
  28:	75 37                	jne    0x61
* 2a:	bf 01 00 00 00       	mov    $0x1,%edi <-- trapping instruction
  2f:	e8 d5 66 19 f6       	call   0xf6196709
  34:	65 8b 05 4e 77 a8 08 	mov    %gs:0x8a8774e(%rip),%eax        # 0x8a87789
  3b:	85 c0                	test   %eax,%eax
  3d:	74 16                	je     0x55
  3f:	5b                   	pop    %rbx