------------[ cut here ]------------
WARNING: CPU: 1 PID: 21220 at kernel/rcu/tree_stall.h:1001 rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:993
Modules linked in:
CPU: 1 PID: 21220 Comm: syz.2.4015 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:1001
Code: ff ff ff 48 c7 c7 a0 14 ef 96 be 04 00 00 00 e8 ea bc 6c 00 48 89 df b8 01 00 00 00 87 05 bc e4 7e 15 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 40 51 d3 8c 74 47 48 c7 c0 1c c2 4a 8e 48 c1 e8 03
RSP: 0018:ffffc900001f0bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffff8cd35140 RCX: ffffffff81702fd6
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8cd35140
RBP: ffffc900001f0e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2dde294 R12: 0000000000002904
R13: 1ffff110171e7a22 R14: 0000000000000a02 R15: dffffc0000000000
FS:  00007f2d3d1c26c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2d3c5e6098 CR3: 0000000059d6f000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 rcu_core+0x612/0x1720 kernel/rcu/tree.c:2462
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254
Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 e9 f6 04 00 00 4c 8b 75 d0 4c 89 e7 e8 70 25 1c 09 e8 1b a3 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90004c1f798 EFLAGS: 00000282
RAX: 8381f28fe8f37200 RBX: 0000000000000000 RCX: 8381f28fe8f37200
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00
RBP: ffffc90004c1f7f0 R08: ffffffff8e4a8d6f R09: 1ffffffff1c951ad
R10: dffffc0000000000 R11: fffffbfff1c951ae R12: ffff888025bc0000
R13: dffffc0000000000 R14: ffff88801b273c00 R15: ffff8880b8f3ccc8
 context_switch kernel/sched/core.c:5383 [inline]
 __schedule+0x14da/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 futex_queue kernel/futex/futex.h:174 [inline]
 futex_wait_queue+0x9d/0x1b0 kernel/futex/waitwake.c:338
 futex_wait+0x19f/0x530 kernel/futex/waitwake.c:656
 do_futex+0x2ff/0x3e0 kernel/futex/syscalls.c:106
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x36f/0x3f0 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2d3c38f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2d3d1c20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f2d3c5e6098 RCX: 00007f2d3c38f6c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2d3c5e6098
RBP: 00007f2d3c5e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2d3c5e6128 R14: 00007ffcdc45b390 R15: 00007ffcdc45b478
 </TASK>
----------------
Code disassembly (best guess):
   0:	0f 84 37 01 00 00    	je     0x13d
   6:	48 85 db             	test   %rbx,%rbx
   9:	0f 85 56 01 00 00    	jne    0x165
   f:	e9 f6 04 00 00       	jmp    0x50a
  14:	4c 8b 75 d0          	mov    -0x30(%rbp),%r14
  18:	4c 89 e7             	mov    %r12,%rdi
  1b:	e8 70 25 1c 09       	call   0x91c2590
  20:	e8 1b a3 2f 00       	call   0x2fa340
  25:	fb                   	sti
  26:	4c 8b 65 c0          	mov    -0x40(%rbp),%r12
* 2a:	49 8d bc 24 f8 15 00 	lea    0x15f8(%r12),%rdi <-- trapping instruction
  31:	00
  32:	48 89 f8             	mov    %rdi,%rax
  35:	48 c1 e8 03          	shr    $0x3,%rax
  39:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
  3e:	84 c0                	test   %al,%al