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1
WARNING: kernel/rcu/tree_stall.h:1048 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048, CPU#0: kworker/0:1H/2238
Modules linked in:
CPU: 0 UID: 0 PID: 2238 Comm: kworker/0:1H Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue:  0x0 (events_highpri)
RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048
Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 80 d5 72 9b e8 60 32 8c 00 b8 01 00 00 00 87 05 f5 ff 83 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 a4 c7 21 91 48 81 fd 40 35 bf 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000007df0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81eed580
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b72d580
RBP: ffffffff8ebf3540 R08: 0000000000000001 R09: fffffbfff36e5ab0
R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1d01e50
R13: 0000000000000246 R14: 0000000000000080 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000015a27d000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1011 [inline]
 rcu_core+0x2cb/0x10d0 kernel/rcu/tree.c:2892
 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:finish_task_switch.isra.0+0x2cd/0x10c0 kernel/sched/core.c:5361
Code: ab 0a 00 00 41 c7 87 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 8d 7f 48 e8 30 a6 e7 09 e8 eb b0 3c 00 fb 48 8d bb f8 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84
RSP: 0018:ffffc900077bfa98 EFLAGS: 00000206
RAX: 0000000000377509 RBX: ffff88802ce2a540 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e1a9056 RDI: ffff88802ce2bc38
RBP: ffffc900077bfaf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88805456ca80
R13: 0000000000000000 R14: ffffffff9121c7a4 R15: ffff8880b843b4c0
 context_switch kernel/sched/core.c:5513 [inline]
 __schedule+0x1264/0x6730 kernel/sched/core.c:7234
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x205/0xa00 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:kthread_data+0x97/0xc0 kernel/kthread.c:237
Code: 02 00 75 46 48 8b 9b 18 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 80 3c 02 00 75 1d 48 8b 43 20 <5b> 5d c3 cc cc cc cc e8 3d af 38 00 90 0f 0b 90 eb a5 e8 c2 3d a9
RSP: 0018:ffffc900077bfd78 EFLAGS: 00000246
RAX: ffff88802bc7d100 RBX: ffff88802bbbc400 RCX: ffffffff81d1c3ea
RDX: 1ffff11005777884 RSI: ffffffff81d1c3f3 RDI: ffff88802bbbc420
RBP: 0000000000200000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000200000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88802bc7d100 R14: ffffed101708750c R15: ffff8880b843a808
 wq_worker_running+0x18/0x260 kernel/workqueue.c:1421
 worker_thread+0x53b/0xe50 kernel/workqueue.c:3501
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	00 00                	add    %al,(%rax)
   2:	41 c7 87 20 0e 00 00 	movl   $0x0,0xe20(%r15)
   9:	00 00 00 00
   d:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  12:	49 8d 7f 48          	lea    0x48(%r15),%rdi
  16:	e8 30 a6 e7 09       	call   0x9e7a64b
  1b:	e8 eb b0 3c 00       	call   0x3cb10b
  20:	fb                   	sti
  21:	48 8d bb f8 16 00 00 	lea    0x16f8(%rbx),%rdi
* 28:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax <-- trapping instruction
  2f:	fc ff df
  32:	48 89 fa             	mov    %rdi,%rdx
  35:	48 c1 ea 03          	shr    $0x3,%rdx
  39:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax
  3d:	84                   	.byte 0x84