rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=e66c/1/0x4000000000000000 softirq=30917/30918 fqs=14
rcu: 	(detected by 0, t=10505 jiffies, g=27629, q=406 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9554 Comm: syz.0.1023 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:rcu_is_watching+0x4/0xb0
Code: 13 8e e8 1f 58 59 03 eb cc 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 <41> 57 41 56 53 65 ff 05 30 5e fa 10 e8 1b ff d3 09 89 c3 83 f8 08
RSP: 0018:ffffc900001e0810 EFLAGS: 00000097
RAX: 0000000000000001 RBX: 0000000000000802 RCX: ffff888106ded640
RDX: 0000000000010000 RSI: ffffffff81ada91e RDI: ffff888136627a98
RBP: ffffc900001e0918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: dffffc0000000000
R13: ffffffff81ada91e R14: ffff888136627a98 R15: 1ffff9200003c110
FS:  00007f75e85596c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c326010 CR3: 000000003a59c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_release+0x4b/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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 5f 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90006a57610 EFLAGS: 00000206
RAX: d7991055a2013200 RBX: 0000000000000000 RCX: d7991055a2013200
RDX: 0000000000000000 RSI: ffffffff8dba98a1 RDI: ffffffff8be33e80
RBP: ffffffff895aa32a R08: 0000000000000000 R09: ffffffff895aa32a
R10: ffffc90006a57800 R11: fffff52000d4af02 R12: 0000000000000000
R13: ffff88802879b1d8 R14: 0000000000000001 R15: 0000000000000246
 _raw_spin_lock_bh+0x36/0x50
 lock_sock_nested+0x6a/0x100
 netlink_insert+0xd3/0x1370
 netlink_autobind+0x22e/0x300
 netlink_sendmsg+0x523/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75e778eba9
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:00007f75e8559038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f75e79d5fa0 RCX: 00007f75e778eba9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f75e7811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75e79d6038 R14: 00007f75e79d5fa0 R15: 00007ffc497746e8
 </TASK>
rcu: rcu_preempt kthread starved for 10435 jiffies! g27629 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: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:
CPU: 0 UID: 0 PID: 9546 Comm: syz.2.1020 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 b6 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 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 45 5f
RSP: 0018:ffffc90006e57580 EFLAGS: 00000293
RAX: ffffffff81b4621b RBX: 1ffff11026cc7f61 RCX: ffff88803cd11cc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90006e57700 R08: ffffffff8fa3a937 R09: 1ffffffff1f47526
R10: dffffc0000000000 R11: fffffbfff1f47527 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75e59f5fc8 CR3: 000000000df36000 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
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9bbb8eba9
Code: Unable to access opcode bytes at 0x7ff9bbb8eb7f.
RSP: 002b:00007ffc2acd9498 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff9bbb8eba9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc2acd94fc R08: 0000001b2acd958f R09: 00000000000927c0
R10: 00000000000001f8 R11: 0000000000000246 R12: 0000000000000160
R13: 00000000000927c0 R14: 0000000000032b81 R15: 00007ffc2acd9550
 </TASK>
