rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=6704/1/0x4000000000000000 softirq=33314/33320 fqs=1
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8058/1:b..l
rcu: 	(detected by 0, t=10506 jiffies, g=32369, q=403 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8035 Comm: syz.7.299 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+0x329/0x2cf0
Code: d6 8b 54 24 20 c1 e2 0f 0f b7 d2 09 f2 41 83 e5 03 41 c1 e5 10 41 09 d5 8b 54 24 10 83 e2 01 c1 e2 12 44 09 ea c1 e3 14 09 d3 <8b> 14 24 c1 e2 13 41 c1 e4 15 41 09 d4 41 09 cc 41 09 dc 45 89 64
RSP: 0018:ffffc90005f9fae0 EFLAGS: 00000006
RAX: 0000000000000005 RBX: 0000000000040000 RCX: 0000000000000204
RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff850234ca R09: ffffffff8f15f3b8
R10: dffffc0000000000 R11: fffffbfff1e2be75 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88816c545880 R15: ffff88816c546410
FS:  000055555add1500(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd969b3aba8 CR3: 00000001b2c06000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350
 _raw_spin_lock_irqsave+0x40/0x60
 vga_arb_release+0x1fa/0x5d0
 __fput+0x44f/0xa60
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xed/0x480
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f87ca19cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff2c04c298 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f87ca417da0 RCX: 00007f87ca19cdd9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f87ca417da0 R08: 00007f87ca416038 R09: 0000000000000000
R10: 000000000003fd3c R11: 0000000000000246 R12: 0000000000028404
R13: 00007f87ca41609c R14: 00000000000282fe R15: 00007f87ca416090
 </TASK>
task:udevadm         state:R  running task     stack:24312 pid:8058  tgid:8058  ppid:7711   task_flags:0x400000 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x14f/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0xf08/0x2550
Code: 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 4c 8b 7c 24 10 74 08 4c 89 ff e8 74 f7 b9 00 49 89 1f 48 8b 44 24 58 80 3c 28 00 <48> 8b 5c 24 78 4c 8b 64 24 18 74 08 48 89 df e8 54 f7 b9 00 4c 89
RSP: 0018:ffffc900070af398 EFLAGS: 00000246
RAX: 1ffff92000e15ea0 RBX: ffffffff81b0d819 RCX: 1ffff92000e15e01
RDX: ffffffff90c3f192 RSI: 0000000000000002 RDI: ffffc900070af558
RBP: dffffc0000000000 R08: 0000000000000007 R09: ffffffff8e95cd60
R10: ffffc900070af518 R11: fffff52000e15ea5 R12: ffffc900070b0000
R13: 1ffff92000e15e9b R14: ffffc900070af4c8 R15: ffffc900070af510
 __unwind_start+0x5b8/0x760
 arch_stack_walk+0xe3/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x2bc/0x650
 security_file_alloc+0x34/0x310
 init_file+0x90/0x2b0
 alloc_empty_file+0x74/0x1d0
 path_openat+0x10f/0x3860
 do_file_open+0x23e/0x4a0
 do_sys_openat2+0x113/0x200
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd969bb2a46
RSP: 002b:00007ffd59f4e8b8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffd59f4eb18 RCX: 00007fd969bb2a46
RDX: 0000000000080000 RSI: 00007ffd59f4e930 RDI: 00000000ffffff9c
RBP: 00007ffd59f4e920 R08: 0000000000080000 R09: 00007ffd59f4e930
R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffd59f4e930
R13: 0000000000000007 R14: 00007ffd59f4eaff R15: 00000000ffffffff
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g32369 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:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 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: 0 UID: 0 PID: 6991 Comm: syz-executor 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+0xfcf/0x13d0
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 7a 05 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 01 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a 01 0c
RSP: 0018:ffffc90005fbf560 EFLAGS: 00000293
RAX: ffffffff81b9ab26 RBX: ffff88812103c148 RCX: ffff888176811d80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005fbf688 R08: ffffffff9030a1f7 R09: 1ffffffff206143e
R10: dffffc0000000000 R11: fffffbfff206143f R12: 1ffff110478c8169
R13: dffffc0000000000 R14: ffff88823c640b48 R15: 0000000000000001
FS:  0000555563e21500(0000) GS:ffff88818dc90000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe336b456b8 CR3: 00000001b284e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x5c3/0x10b0
 dup_mmap+0x17a2/0x1d90
 copy_mm+0x13b/0x4a0
 copy_process+0x1f1c/0x4450
 kernel_clone+0x284/0x8f0
 __x64_sys_clone+0x1b6/0x230
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe335dc5852
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffcb7f72130 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffcb7f72130 RCX: 00007fe335dc5852
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffcb7f722bc R08: 0000000000000000 R09: 0000000000000001
R10: 0000555563e217d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000028231 R15: 00007ffcb7f72310
 </TASK>
