------------[ 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#0: pr/ttyS0/32
Modules linked in:
CPU: 0 UID: 0 PID: 32 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:mce_timer_fn+0x289/0x2e0 arch/x86/kernel/cpu/mce/core.c:1770
Code: 59 00 4d 01 e4 4d 39 ec 4d 0f 47 e5 31 ff 4c 89 e6 e8 4b 3f 59 00 4d 85 e4 0f 84 20 ff ff ff e9 f7 fe ff ff e8 98 44 59 00 90 <0f> 0b 90 e9 cf fd ff ff 4c 89 f6 48 c7 c7 a0 ef bf 8f e8 e0 d0 84
RSP: 0018:ffffc90000007c20 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880b8223440 RCX: 0000000000000101
RDX: ffff8880206e8000 RSI: ffffffff81b301b8 RDI: ffffffff8e6ae920
RBP: ffff8880b8323440 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000000762b R12: 0000000000000000
R13: 0000000000000101 R14: 1ffff92000000f8d R15: ffffffff81b2ff30
FS: 0000000000000000(0000) GS:ffff888122944000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0e4786064c CR3: 000000005d319000 CR4: 0000000000350ef0
Call Trace:
call_timer_fn+0x198/0x5f0 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+0x1e6/0x9d0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
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
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:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:221
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 36 bb 10 f6 48 89 df e8 be 11 11 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 05 f5 ff f5 65 48 83 3d 74 03 b7 09 00 74 16 5b
RSP: 0018:ffffc90000a87ca8 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff9cc72ba0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8e3e3167 RDI: ffffffff8c625c80
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 7a7973203a6d6d43 R12: 1ffff92000150f98
R13: ffffffff90bdd360 R14: 0000000000000001 R15: 0000000000000000
nbcon_emit_one+0x15c/0x2b0 kernel/printk/nbcon.c:1165
nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
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 36 bb 10 f6 call 0xf610bb49
13: 48 89 df mov %rbx,%rdi
16: e8 be 11 11 f6 call 0xf61111d9
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 05 f5 ff f5 call 0xf5fff539
34: 65 48 83 3d 74 03 b7 cmpq $0x0,%gs:0x9b70374(%rip) # 0x9b703b1
3b: 09 00
3d: 74 16 je 0x55
3f: 5b pop %rbx