rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=5f04/1/0x4000000000000000 softirq=68022/68031 fqs=0
rcu: 	(detected by 1, t=10506 jiffies, g=64641, q=304 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5045 Comm: udevd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:lock_release+0xe8/0x3c0
Code: 8b 87 98 0b 00 00 85 c0 0f 84 17 01 00 00 4c 89 6c 24 18 48 89 5c 24 08 44 8d 60 ff 49 8d af a0 0b 00 00 4d 63 ec 48 89 04 24 <83> f8 32 0f 83 2a 02 00 00 4a 8d 1c ad 00 00 00 00 4c 01 eb 48 8d
RSP: 0018:ffffc90000007c98 EFLAGS: 00000002
RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000080010001
RDX: 0000000000010000 RSI: ffffffff8e241e25 RDI: ffffffff8c4bb580
RBP: ffff88811627c720 R08: ffff88810e2af083 R09: 1ffff11021c55e10
R10: dffffc0000000000 R11: ffffed1021c55e11 R12: 0000000000000001
R13: 0000000000000001 R14: ffff888021ab82c0 R15: ffff88811627bb80
FS:  00007f0f8a2c0c80(0000) GS:ffff88818d959000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c379a53 CR3: 00000001163bc000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 _raw_spin_unlock+0x16/0x50
 advance_sched+0x99a/0xc80
 __hrtimer_run_queues+0x3bc/0xa10
 hrtimer_interrupt+0x448/0x910
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:inode_permission+0x3ae/0x5f0
Code: 3c 08 00 74 08 4c 89 ef e8 5f 33 ea ff 4d 8b 6d 00 49 83 c5 10 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 4c 89 ef e8 38 33 ea ff 4d 8b 6d 00 4d 85 ed 0f 84 07 01 00
RSP: 0018:ffffc9000277fa10 EFLAGS: 00000246
RAX: 1ffffffff1804b52 RBX: 1ffff1102cf7ca60 RCX: dffffc0000000000
RDX: ffff88811627bb80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff888160ac0220 R09: ffff888167bf2a48
R10: ffff888160ac0220 R11: ffff888167bf2a48 R12: ffff888167be5302
R13: ffffffff8c025a90 R14: ffff888167be5300 R15: 0000000000000081
 link_path_walk+0xaa6/0x1910
 path_lookupat+0xe4/0x8c0
 filename_lookup+0x265/0x5d0
 do_readlinkat+0xe3/0x510
 __x64_sys_readlink+0x7f/0x90
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0f89f17d47
Code: 73 01 c3 48 8b 0d e1 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 90 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007fff5b9e4368 EFLAGS: 00000206 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0f89f17d47
RDX: 0000000000000400 RSI: 00007fff5b9e4778 RDI: 00007fff5b9e4378
RBP: 00007fff5b9e4bb8 R08: 000000000000feff R09: 0000000000000000
R10: 0000000000000010 R11: 0000000000000206 R12: 0000000000000200
R13: 00007fff5b9e4778 R14: 00007fff5b9e4378 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10506 jiffies! g64641 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27496 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 12438 Comm: syz.7.1310 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0x10b0/0x14b0
Code: c0 75 73 41 8b 1e 89 de 83 e6 01 31 ff e8 d8 22 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1e 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1e 0c
RSP: 0018:ffffc90008df7580 EFLAGS: 00000293
RAX: ffffffff81bad317 RBX: dffffc0000000000 RCX: ffff88810fa43b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90008df76a8 R08: ffffffff90575937 R09: 1ffffffff20aeb26
R10: dffffc0000000000 R11: fffffbfff20aeb27 R12: 1ffff110242085fd
R13: ffff88823c63c448 R14: ffff888121042fe8 R15: 0000000000000000
FS:  00007fafe9e736c0(0000) GS:ffff8882a8f59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fafdecff000 CR3: 00000001bb376000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x5c4/0x1090
 tlb_flush_mmu+0x1af/0xa30
 tlb_finish_mmu+0xf4/0x220
 unmap_region+0x2a5/0x330
 vms_complete_munmap_vmas+0x427/0xbe0
 do_vmi_align_munmap+0x3b7/0x4b0
 do_vmi_munmap+0x252/0x2d0
 __vm_munmap+0x241/0x3e0
 __x64_sys_munmap+0x60/0x70
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fafe8f9df87
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fafe9e72e08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007fafe8f9df87
RDX: 0000000000100000 RSI: 0000000008400000 RDI: 00007fafdec00000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 00007fafe9e72ee0 R14: 00007fafe9e72ea0 R15: 00007fafdec00000
 </TASK>
