------------[ cut here ]------------
WARNING: CPU: 1 PID: 9562 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: 9562 Comm: syz.2.985 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:1001
Code: ff ff ff 48 c7 c7 a0 04 33 97 be 04 00 00 00 e8 0a 11 6e 00 48 89 df b8 01 00 00 00 87 05 6c b6 c1 15 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 00 70 13 8d 74 47 48 c7 c0 dc 9f 8c 8e 48 c1 e8 03
RSP: 0018:ffffc900001f0bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffff8d137000 RCX: ffffffff81714e26
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8d137000
RBP: ffffc900001f0e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2e66094 R12: 0000000000002904
R13: 1ffff9200003e194 R14: 0000000000000a02 R15: dffffc0000000000
FS:  00007f4fbb28c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000002b43a000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 rcu_core+0x5ec/0x17f0 kernel/rcu/tree.c:2462
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 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:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:216
Code: 89 fb e8 13 00 00 00 48 8b 3d ec 87 05 0d 48 89 de 5b e9 23 a7 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d c0 d2 7c 7e <65> 8b 15 c1 d2 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc9000f067bf8 EFLAGS: 00000246
RAX: ffffffff812e4996 RBX: ffffc9000f067ff8 RCX: ffff88802be85a00
RDX: ffff88802be85a00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000f067d70 R08: ffffffff8e8c6b2f R09: 1ffffffff1d18d65
R10: dffffc0000000000 R11: fffffbfff1d18d66 R12: 00007f4fbb28bb38
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88802be86320
 x64_setup_rt_frame+0x766/0xc30 arch/x86/kernel/signal_64.c:194
 setup_rt_frame arch/x86/kernel/signal.c:223 [inline]
 handle_signal arch/x86/kernel/signal.c:267 [inline]
 arch_do_signal_or_restart+0x411/0x7b0 arch/x86/kernel/signal.c:312
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4fba39de57
Code: 83 c8 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
RSP: 002b:00007f4fbb28c0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f4fba625fa8 RCX: 00007f4fba39de59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f4fba625fa8
RBP: 00007f4fba625fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4fba626038 R14: 00007ffcef947ff0 R15: 00007ffcef9480d8
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 fb                	mov    %edi,%ebx
   2:	e8 13 00 00 00       	call   0x1a
   7:	48 8b 3d ec 87 05 0d 	mov    0xd0587ec(%rip),%rdi        # 0xd0587fa
   e:	48 89 de             	mov    %rbx,%rsi
  11:	5b                   	pop    %rbx
  12:	e9 23 a7 57 00       	jmp    0x57a73a
  17:	cc                   	int3
  18:	cc                   	int3
  19:	cc                   	int3
  1a:	f3 0f 1e fa          	endbr64
  1e:	48 8b 04 24          	mov    (%rsp),%rax
  22:	65 48 8b 0d c0 d2 7c 	mov    %gs:0x7e7cd2c0(%rip),%rcx        # 0x7e7cd2ea
  29:	7e
* 2a:	65 8b 15 c1 d2 7c 7e 	mov    %gs:0x7e7cd2c1(%rip),%edx        # 0x7e7cd2f2 <-- trapping instruction
  31:	81 e2 00 01 ff 00    	and    $0xff0100,%edx
  37:	74 11                	je     0x4a
  39:	81 fa 00 01 00 00    	cmp    $0x100,%edx
  3f:	75                   	.byte 0x75