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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#0: syz.5.2587/15394
Modules linked in:
CPU: 0 UID: 0 PID: 15394 Comm: syz.5.2587 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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 12 f4 9a e8 a0 4c 85 00 b8 01 00 00 00 87 05 d5 0c 08 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 d4 7c b7 90 48 81 fd 40 f3 5e 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000007df8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ec05e0
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9af412c0
RBP: ffffffff8e5ef340 R08: 0000000000000001 R09: fffffbfff35e8258
R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1c42250
R13: 0000000000000246 R14: ffffffff8e5ef340 R15: ffff8880b843bc52
FS:  00007f7d888f86c0(0000) GS:ffff8881245d9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000140 CR3: 000000007e7b6000 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:__exit_to_user_mode_loop kernel/entry/common.c:31 [inline]
RIP: 0010:exit_to_user_mode_loop+0x65/0x4b0 kernel/entry/common.c:75
Code: 9c 58 fa f6 c4 02 0f 85 91 00 00 00 e8 34 65 87 09 49 8b 1c 24 f7 c3 37 03 00 00 0f 84 86 00 00 00 e8 cf 6b 1f 00 fb f6 c3 30 <74> c5 e8 54 7d 88 09 f6 c7 01 74 c0 48 89 ef e8 f7 16 4e 00 f6 c3
RSP: 0018:ffffc90005957ed8 EFLAGS: 00000246
RAX: 000000000684ba3b RBX: 0000000000080002 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8dc45690 RDI: ffffffff8bfa3620
RBP: ffffc90005957f48 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802ef90000
R13: 0000000000080002 R14: 00000000000000ca R15: 00000000000000ca
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7d8799aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7d888f80e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7d87c15fa8 RCX: 00007f7d8799aeb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7d87c15fa8
RBP: 00007f7d87c15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7d87c16038 R14: 00007ffed19f8590 R15: 00007ffed19f8678
 </TASK>
----------------
Code disassembly (best guess):
   0:	9c                   	pushf
   1:	58                   	pop    %rax
   2:	fa                   	cli
   3:	f6 c4 02             	test   $0x2,%ah
   6:	0f 85 91 00 00 00    	jne    0x9d
   c:	e8 34 65 87 09       	call   0x9876545
  11:	49 8b 1c 24          	mov    (%r12),%rbx
  15:	f7 c3 37 03 00 00    	test   $0x337,%ebx
  1b:	0f 84 86 00 00 00    	je     0xa7
  21:	e8 cf 6b 1f 00       	call   0x1f6bf5
  26:	fb                   	sti
  27:	f6 c3 30             	test   $0x30,%bl
* 2a:	74 c5                	je     0xfffffff1 <-- trapping instruction
  2c:	e8 54 7d 88 09       	call   0x9887d85
  31:	f6 c7 01             	test   $0x1,%bh
  34:	74 c0                	je     0xfffffff6
  36:	48 89 ef             	mov    %rbp,%rdi
  39:	e8 f7 16 4e 00       	call   0x4e1735
  3e:	f6                   	.byte 0xf6
  3f:	c3                   	ret