------------[ cut here ]------------
WARNING: CPU: 2 PID: 0 at kernel/rcu/tree_stall.h:824 rcu_check_gp_start_stall.part.0+0x325/0x4b0 kernel/rcu/tree_stall.h:816
Modules linked in:
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:rcu_check_gp_start_stall.part.0+0x325/0x4b0 kernel/rcu/tree_stall.h:824
Code: 0f 88 fa 00 00 00 be 04 00 00 00 48 c7 c7 20 75 e4 8f e8 3e b5 56 00 b8 01 00 00 00 87 05 83 e8 84 0e 85 c0 0f 85 c9 00 00 00 <0f> 0b 48 81 fd c0 9d f7 8b 48 c7 c3 4c 1b c6 8d 74 58 48 b8 00 00
RSP: 0018:ffffc90000570e50 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000010000fc5e RCX: ffffffff815f8c92
RDX: fffffbfff1fc8ea4 RSI: 0000000000000004 RDI: ffffffff8fe47520
RBP: ffffffff8bf79dc0 R08: 0000000000000001 R09: 0000000000000003
R10: fffffbfff1fc8ea4 R11: 1ffff11005986c2e R12: 1ffffffff1781e30
R13: 0000000000000246 R14: ffff88802cc36092 R15: ffff88802cc36118
FS:  0000000000000000(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4ab1d4fab4 CR3: 0000000014432000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:787 [inline]
 rcu_core+0x4ec/0x12f0 kernel/rcu/tree.c:2789
 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu kernel/softirq.c:422 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:default_idle+0xe/0x10 arch/x86/kernel/process.c:689
Code: ff ff ff 48 89 df e8 61 b1 ad f8 e9 52 ff ff ff 4c 89 e7 e8 54 b1 ad f8 eb 93 66 90 e9 07 00 00 00 0f 00 2d 24 61 5d 00 fb f4 <c3> cc 41 55 41 54 55 48 89 fd 53 e8 82 95 6a f8 e8 6d af fd ff 48
RSP: 0018:ffffc9000045fdf8 EFLAGS: 00000202
RAX: 0000000000627923 RBX: ffff8880112be0c0 RCX: ffffffff89063140
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffed1002257c18 R08: 0000000000000001 R09: ffff88802cc361cb
R10: ffffed1005986c39 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8dc5ea48 R15: 0000000000000000
 default_idle_call+0x87/0xd0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x3fa/0x590 kernel/sched/idle.c:300
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:397
 start_secondary+0x274/0x350 arch/x86/kernel/smpboot.c:272
 secondary_startup_64_no_verify+0xb0/0xbb