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WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#1: swapper/1/0
Modules linked in:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049
Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 c0 e2 f3 9a e8 20 48 85 00 b8 01 00 00 00 87 05 d5 d6 07 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 74 68 b7 90 48 81 fd c0 f3 5e 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000a08df8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ec0be0
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9af3e2c0
RBP: ffffffff8e5ef3c0 R08: 0000000000000001 R09: fffffbfff35e7c58
R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1c42250
R13: 0000000000000246 R14: ffffffff8e5ef3c0 R15: ffff8880b853bc52
FS:  0000000000000000(0000) GS:ffff8881246dc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5c3d0aff8 CR3: 0000000050b17000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline]
 rcu_core+0x4e8/0x15c0 kernel/rcu/tree.c:2852
 handle_softirqs+0x1ea/0x910 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:sched_core_balance+0x9f/0xe10 kernel/sched/core.c:6288
Code: 33 5e 8e e8 43 e2 0d 00 e8 ae 66 a1 09 41 5a 85 c0 0f 85 1c 0a 00 00 4c 89 ef e8 cc 34 ff ff e8 97 a7 39 00 fb 48 63 44 24 50 <48> c7 c3 80 ec e5 93 48 89 dd 48 89 44 24 08 48 83 f8 08 0f 83 40
RSP: 0018:ffffc90000197b60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: ffff8880b853ac80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8dc45440 RDI: ffffffff8bfa35a0
RBP: ffffc90000197c78 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801e2ba4c0
R13: ffff8880b853ac80 R14: 0000000000000000 R15: dffffc0000000000
 do_balance_callbacks kernel/sched/core.c:4901 [inline]
 __balance_callbacks kernel/sched/core.c:4957 [inline]
 finish_lock_switch kernel/sched/core.c:4998 [inline]
 finish_task_switch.isra.0+0x443/0xb70 kernel/sched/core.c:5116
 context_switch kernel/sched/core.c:5263 [inline]
 __schedule+0xfec/0x5e10 kernel/sched/core.c:6867
 schedule_idle+0x54/0x80 kernel/sched/core.c:6990
 do_idle+0x289/0x4b0 kernel/sched/idle.c:360
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>
----------------
Code disassembly (best guess):
   0:	33 5e 8e             	xor    -0x72(%rsi),%ebx
   3:	e8 43 e2 0d 00       	call   0xde24b
   8:	e8 ae 66 a1 09       	call   0x9a166bb
   d:	41 5a                	pop    %r10
   f:	85 c0                	test   %eax,%eax
  11:	0f 85 1c 0a 00 00    	jne    0xa33
  17:	4c 89 ef             	mov    %r13,%rdi
  1a:	e8 cc 34 ff ff       	call   0xffff34eb
  1f:	e8 97 a7 39 00       	call   0x39a7bb
  24:	fb                   	sti
  25:	48 63 44 24 50       	movslq 0x50(%rsp),%rax
* 2a:	48 c7 c3 80 ec e5 93 	mov    $0xffffffff93e5ec80,%rbx <-- trapping instruction
  31:	48 89 dd             	mov    %rbx,%rbp
  34:	48 89 44 24 08       	mov    %rax,0x8(%rsp)
  39:	48 83 f8 08          	cmp    $0x8,%rax
  3d:	0f                   	.byte 0xf
  3e:	83                   	.byte 0x83
  3f:	40                   	rex