rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=cebc/1/0x4000000000000000 softirq=48998/49006 fqs=0
rcu: 	(detected by 0, t=10505 jiffies, g=46973, q=82 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14044 Comm: syz.1.2487 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:lock_acquire+0xbf/0x360
Code: 84 fa 00 00 00 65 8b 05 5f a0 03 11 85 c0 0f 85 eb 00 00 00 65 48 8b 04 25 08 d0 a0 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 <48> c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89 74 24 10 4d 89 fe
RSP: 0018:ffffc900001e07e0 EFLAGS: 00000046
RAX: ffff888109348000 RBX: 0000000000000000 RCX: 3fa97c3ea66c1300
RDX: 0000000000000000 RSI: ffffffff8b7cebf7 RDI: 1ffff11026cc4f53
RBP: ffffffff81ada78b R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: 0000000000000000
R13: ffff888136627a98 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f22476476c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000d000 CR3: 000000011d2e8000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_lock_irqsave+0xa7/0xf0
 hrtimer_try_to_cancel+0x22b/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:futex_wake+0x5/0x560
Code: 00 e9 39 ff ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00
RSP: 0018:ffffc90008dcfcf0 EFLAGS: 00000283
RAX: ffffffff81b3640d RBX: dffffc0000000000 RCX: 00000000ffffffff
RDX: 00000000000f4240 RSI: 0000000000000002 RDI: 00007f22469d5fac
RBP: ffffc90008dcfdc8 R08: ffff888109348000 R09: 000000000000000d
R10: 000000000000000d R11: 0000000000000002 R12: ffffc90008dcfd60
R13: 0000000000000001 R14: 1ffff920011b9fa8 R15: 0000000000000000
 do_futex+0x395/0x420
 __se_sys_futex+0x36f/0x400
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f224678eba9
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:00007f22476470e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f22469d5fa8 RCX: 00007f224678eba9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f22469d5fac
RBP: 00007f22469d5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f22469d6038 R14: 00007ffed55295d0 R15: 00007ffed55296b8
 </TASK>
rcu: rcu_preempt kthread starved for 10505 jiffies! g46973 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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  running task     stack:26440 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:
CPU: 0 UID: 0 PID: 14042 Comm: syz.0.2486 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:smp_call_function_many_cond+0xd33/0x12d0
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 56 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 01 5f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 e5 5e
RSP: 0018:ffffc90008e7f540 EFLAGS: 00000246
RAX: ffffffff81b4621b RBX: 1ffff11026cc7f61 RCX: 0000000000080000
RDX: ffffc900037f2000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90008e7f6c0 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
FS:  00007fce5b5b96c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c296bf2 CR3: 0000000028a2e000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 dup_mmap+0x15a0/0x1ac0
 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: 0033:0x7fce5a78eba9
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:00007fce5b5b8fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fce5a9d5fa0 RCX: 00007fce5a78eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fce5a811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce5a9d6038 R14: 00007fce5a9d5fa0 R15: 00007ffd9beb4f98
 </TASK>
