rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10506 jiffies, g=15537, q=207 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4294958381-4294947875), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g15537 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=5632
rcu: rcu_preempt kthread starved for 10506 jiffies! g15537 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R stack:27160 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7327 Comm: syz.1.320 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:its_return_thunk+0x0/0x10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 32 b6 f5 cc
RSP: 0018:ffffc90000007810 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000014 RCX: 2731bb8f6e351500
RDX: 0000000000010000 RSI: ffff88804b027a98 RDI: ffff8880234c0b90
RBP: ffff8880234c0b90 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: 0000000000000004
R13: 0000000000000004 R14: ffff88804b027a98 R15: ffff8880234c0000
FS:  00007fba1fa106c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c36eb09 CR3: 0000000030140000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_release+0x127/0x3e0
 _raw_spin_unlock_irqrestore+0x70/0x110
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x243/0x2390
Code: 0f 85 1c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d 2c 85 24 4f e0 90 48 89 e8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 1c 1c 00 00 <44> 8b 45 00 41 ff c0 4a 8d 04 6d 00 00 00 00 4c 01 e8 48 8d 34 45
RSP: 0018:ffffc9000257f258 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 2731bb8f6e351500
RDX: 00000000000a7e25 RSI: ffffffff8be33de0 RDI: ffffffff8be33da0
RBP: ffffffff90e30058 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc9000257f378 R11: ffffffff81ac4d00 R12: ffffffff81ac4cab
R13: 000000000002328c R14: ffffc9000257f328 R15: 000000000000ac4c
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 anon_vma_clone+0xb8/0x4f0
 anon_vma_fork+0x79/0x500
 dup_mmap+0x9eb/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba1eb8eba9
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:00007fba1fa0ffe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fba1edd5fa0 RCX: 00007fba1eb8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000020000
RBP: 00007fba1ec11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fba1edd6038 R14: 00007fba1edd5fa0 R15: 00007ffc99883db8
 </TASK>
