------------[ cut here ]------------
WARNING: CPU: 0 PID: 13971 at kernel/rcu/tree_stall.h:937 rcu_check_gp_start_stall+0x2c8/0x450 kernel/rcu/tree_stall.h:922
Modules linked in:
CPU: 0 PID: 13971 Comm: syz.0.2202 Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:rcu_check_gp_start_stall+0x2c8/0x450 kernel/rcu/tree_stall.h:937
Code: c7 c7 60 cc 4a 91 be 04 00 00 00 e8 62 99 5e 00 b8 01 00 00 00 87 05 d7 2e df 0f 85 c0 0f 85 1c ff ff ff 48 c7 c0 c0 3a 92 8c <0f> 0b 49 39 c7 74 47 48 c7 c0 c4 7f e9 8d 48 c1 e8 03 42 0f b6 04
RSP: 0018:ffffc90000007bd8 EFLAGS: 00010046
RAX: ffffffff8c923ac0 RBX: 0000000100012167 RCX: ffffffff816b9d7e
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff914acc60
RBP: ffffc90000007e10 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c923ac0
FS:  00005555573d4500(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1823f9000 CR3: 000000001f48c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_core+0x657/0x1650 kernel/rcu/tree.c:2758
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__might_fault+0x7/0x110 mm/memory.c:5314
Code: 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 d2 96 c6 ff 4c 89 f7 31 f6 e8 68 12 fe ff e9 dd fe ff ff 0f 1f 00 55 41 57 41 56 41 54 <53> 41 89 f6 49 89 ff 49 bc 00 00 00 00 00 fc ff df e8 a3 96 c6 ff
RSP: 0018:ffffc90002e079b8 EFLAGS: 00000293
RAX: ffffffff812f3097 RBX: 00007ffd39d01580 RCX: ffff888023181dc0
RDX: 0000000000000000 RSI: 000000000000008f RDI: ffffffff8a85e180
RBP: ffffc90002e07b70 R08: ffffffff812f2cc4 R09: ffffed10046303b9
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110046306a9
R13: 0000000000000007 R14: ffff888023181dc0 R15: dffffc0000000000
 __copy_to_user include/linux/uaccess.h:143 [inline]
 save_xstate_epilog arch/x86/kernel/fpu/signal.c:104 [inline]
 copy_fpstate_to_sigframe+0x858/0xb40 arch/x86/kernel/fpu/signal.c:217
 get_sigframe+0x378/0x4b0 arch/x86/kernel/signal.c:295
 __setup_rt_frame arch/x86/kernel/signal.c:471 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
 handle_signal arch/x86/kernel/signal.c:824 [inline]
 arch_do_signal_or_restart+0x4ac/0x1890 arch/x86/kernel/signal.c:869
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe1840a23d0
Code: 10 83 e0 01 83 e2 01 88 15 1a 93 e0 00 88 05 17 93 e0 00 c3 50 48 8d 35 10 b5 1a 00 48 8d 3d 16 b5 1a 00 31 c0 e8 d0 f8 ff ff <53> 89 fb 48 83 ec 10 64 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31
RSP: 002b:00007ffd39d01978 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 00007fe18437c208 RCX: 0000001b2bd20000
RDX: 00007ffd39d01980 RSI: 00007ffd39d01ab0 RDI: 0000000000000007
RBP: 00007fe18437da80 R08: 00000000003ffb04 R09: 0000000000000006
R10: 0000001b2bd20210 R11: 000000000000000a R12: 00000000000e4e56
R13: 00007ffd39d02030 R14: 00007ffd39d02050 R15: ffffffffffffffff
 </TASK>
----------------
Code disassembly (best guess):
   0:	10 5b 41             	adc    %bl,0x41(%rbx)
   3:	5c                   	pop    %rsp
   4:	41 5d                	pop    %r13
   6:	41 5e                	pop    %r14
   8:	41 5f                	pop    %r15
   a:	5d                   	pop    %rbp
   b:	c3                   	ret
   c:	e8 d2 96 c6 ff       	call   0xffc696e3
  11:	4c 89 f7             	mov    %r14,%rdi
  14:	31 f6                	xor    %esi,%esi
  16:	e8 68 12 fe ff       	call   0xfffe1283
  1b:	e9 dd fe ff ff       	jmp    0xfffffefd
  20:	0f 1f 00             	nopl   (%rax)
  23:	55                   	push   %rbp
  24:	41 57                	push   %r15
  26:	41 56                	push   %r14
  28:	41 54                	push   %r12
* 2a:	53                   	push   %rbx <-- trapping instruction
  2b:	41 89 f6             	mov    %esi,%r14d
  2e:	49 89 ff             	mov    %rdi,%r15
  31:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
  38:	fc ff df
  3b:	e8 a3 96 c6 ff       	call   0xffc696e3