------------[ cut here ]------------
WARNING: CPU: 3 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: 3 PID: 0 Comm: swapper/3 Not tainted 5.12.0-rc8-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 95 e2 8f e8 6e 5a 57 00 b8 01 00 00 00 87 05 e3 3b 82 0e 85 c0 0f 85 c9 00 00 00 <0f> 0b 48 81 fd 00 c9 f7 8b 48 c7 c3 0c 5c c5 8d 74 58 48 b8 00 00
RSP: 0018:ffffc900005a8e50 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000100001100 RCX: ffffffff81605932
RDX: fffffbfff1fc52a4 RSI: 0000000000000004 RDI: ffffffff8fe29520
RBP: ffffffff8bf7c900 R08: 0000000000000001 R09: 0000000000000003
R10: fffffbfff1fc52a4 R11: ffffffff8bf7c940 R12: 1ffffffff1781e30
R13: 0000000000000246 R14: ffff88802cd35fd2 R15: ffff88802cd36058
FS:  0000000000000000(0000) GS:ffff88802cd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f22f4e21000 CR3: 000000001cb5c000 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 d1 15 b2 f8 e9 52 ff ff ff 4c 89 e7 e8 c4 15 b2 f8 eb 93 66 90 e9 07 00 00 00 0f 00 2d 04 53 60 00 fb f4 <c3> cc 41 55 41 54 55 48 89 fd 53 e8 c2 5a 6e f8 e8 7d b3 fd ff 48
RSP: 0018:ffffc9000044fdf8 EFLAGS: 00000202
RAX: 000000000028bccd RBX: ffff888010c9b880 RCX: ffffffff890342b0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffed1002193710 R08: 0000000000000001 R09: ffff88802cd3610b
R10: ffffed10059a6c21 R11: 0000000000000000 R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff8dc52b08 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