rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=18e4/1/0x4000000000000000 softirq=21018/21019 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=12177, q=460 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6583 Comm: syz.2.158 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+0x12/0x360
Code: cc 0f 1f 80 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 41 57 41 56 41 55 41 54 53 48 83 ec 60 <4d> 89 ce 45 89 c7 41 89 cc 89 54 24 04 89 f3 49 89 fd 48 8b ac 24
RSP: 0018:ffffc900001dfde0 EFLAGS: 00000082
RAX: 0000000000010102 RBX: ffff888136627ac0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888136627ad8
RBP: ffffc900001dff18 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1026cc4f59 R12: dffffc0000000000
R13: ffff888136627b40 R14: 0000000000000802 R15: 1ffff9200003bfd0
FS:  00007ff21b5656c0(0000) GS:ffff8881a4173000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30c17ff8 CR3: 000000010f34a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 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+0x3b8/0x500
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x7cd/0x2390
Code: 0f 84 d3 0d 00 00 48 83 c7 38 e8 0e 28 00 00 49 89 c4 48 8b 34 24 e9 a9 02 00 00 49 8d 5e 40 48 89 d8 48 c1 e8 03 80 3c 28 00 <74> 11 48 89 df e8 c9 bb b0 00 48 8b 34 24 48 8b 54 24 08 4c 8b 23
RSP: 0018:ffffc900001e06b8 EFLAGS: 00000246
RAX: 1ffff9200003c105 RBX: ffffc900001e0828 RCX: ffffffff8f6f7260
RDX: ffffffff8fe94dd6 RSI: ffffffff8fe94dda RDI: ffffffff8b9ec280
RBP: dffffc0000000000 R08: 0000000000000007 R09: ffffffff81725d05
R10: ffffc900001e0838 R11: fffff5200003c109 R12: ffffffff8fe94ddb
R13: ffffc900001e0838 R14: ffffc900001e07e8 R15: ffffc900001e0820
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:raw_spin_rq_unlock_irq+0x13/0x90
Code: cc e8 11 89 a6 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 66 90 e8 94 1f a9 09 e8 7f 4c 35 00 fb 5b <41> 5e 41 5f e9 d4 6d a9 09 cc f3 0f 1e fa 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc90004dc76e8 EFLAGS: 00000282
RAX: 803e8a2990b73f00 RBX: ffff888136639fc0 RCX: 803e8a2990b73f00
RDX: 0000000000000000 RSI: ffffffff8d53a1aa RDI: ffffffff8b9ec2e0
RBP: ffffc90004dc7910 R08: ffffffff8f5cd537 R09: 1ffffffff1eb9aa6
R10: dffffc0000000000 R11: fffffbfff1eb9aa7 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88801ff8ba00 R15: 1ffff11026cc7558
 __schedule+0x19e0/0x4cc0
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 _raw_spin_unlock_irq+0x45/0x50
 copy_process+0x501/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff21a78ec29
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:00007ff21b564fe8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ff21a9d5fa0 RCX: 00007ff21a78ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000a49a4080
RBP: 00007ff21a811e41 R08: ffffffffff600000 R09: ffffffffff600000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ff21a9d6038 R14: 00007ff21a9d5fa0 R15: 00007ffdb461d368
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g12177 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:27432 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
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: 6537 Comm: syz.2.147 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+0xd38/0x12d0
Code: 89 ee 83 e6 01 31 ff e8 a6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 51 6f 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 35 6f 0b 00 eb e4 44
RSP: 0018:ffffc90006627380 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff11026cc7f61 RCX: ffff88810a059d00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90006627500 R08: ffffffff8f5cd537 R09: 1ffffffff1eb9aa6
R10: dffffc0000000000 R11: fffffbfff1eb9aa7 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b23b1c0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8d73000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000db36000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 free_ldt_pgtables+0x17b/0x320
 exit_mmap+0x17c/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1285/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 irqentry_exit_to_user_mode+0x7e/0x110
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7ff21a78ec31
Code: Unable to access opcode bytes at 0x7ff21a78ec07.
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007ff21a9d5fa0 RCX: 00007ff21a78ec29
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007ff21a811e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ff21a9d6038 R14: 00007ff21a9d5fa0 R15: 00007ffdb461d368
 </TASK>
