rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=ea1c/1/0x4000000000000000 softirq=26332/26332 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5298/1:b..l
rcu: 	(detected by 0, t=10506 jiffies, g=19409, q=516 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8279 Comm: syz.1.695 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+0x292/0xd20
Code: fd 31 48 89 74 24 20 0f 83 5e 0a 00 00 4c 89 6c 24 28 4a 8d 04 ad 00 00 00 00 4c 01 e8 89 f1 81 e1 ff 1f 00 00 ba 00 e0 ff ff <41> 23 54 c7 20 09 ca 41 89 54 c7 20 4d 89 4c c7 08 49 89 5c c7 10
RSP: 0018:ffffc900001e0750 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff888136627a98 RCX: 0000000000000067
RDX: 00000000ffffe000 RSI: 0000000000000067 RDI: ffff888022cf1cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888022cf27b0
FS:  00007f3a198e96c0(0000) GS:ffff8881a3c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003d6bc000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360
 _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:_raw_spin_unlock_irqrestore+0xa8/0x110
Code: 74 05 e8 2b 0c 4a f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e3 b0 12 f6 65 8b 05 6c 81 23 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900066ffaa0 EFLAGS: 00000206
RAX: a04c34c88baede00 RBX: 0000000000000a02 RCX: a04c34c88baede00
RDX: 0000000000000000 RSI: ffffffff8d9baa25 RDI: 0000000000000001
RBP: ffffc900066ffb28 R08: ffffffff8fa3b237 R09: 1ffffffff1f47646
R10: dffffc0000000000 R11: fffffbfff1f47647 R12: dffffc0000000000
R13: 1ffff11026cc75be R14: ffff88812e928a10 R15: 1ffff92000cdff54
 try_to_wake_up+0x7b7/0x12b0
 wake_up_q+0x85/0xd0
 futex_wake+0x4a0/0x560
 do_futex+0x395/0x420
 __se_sys_futex+0x36f/0x400
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a1898ec29
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:00007f3a198e90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f3a18bd5fa8 RCX: 00007f3a1898ec29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f3a18bd5fac
RBP: 00007f3a18bd5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a18bd6038 R14: 00007ffcf3b663d0 R15: 00007ffcf3b664b8
 </TASK>
task:udevd           state:R  running task     stack:25064 pid:5298  tgid:5298  ppid:1      task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0xc2/0x2390
Code: 00 e8 f2 59 34 00 4c 8d 3d 00 00 00 00 48 c7 c7 20 a1 13 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 41 57 e8 7e 9d 2a 00 <48> 83 c4 08 e8 25 fd 07 0a 85 c0 74 3a e8 2c a0 33 00 84 c0 75 31
RSP: 0018:ffffc9000273f590 EFLAGS: 00000282
RAX: 841941f5cc650000 RBX: ffffffff8172fa38 RCX: 841941f5cc650000
RDX: 0000000000000000 RSI: ffffffff8dbaa0c3 RDI: ffffffff8be34280
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc9000273f6c8 R11: fffff520004e7ee5 R12: 1ffff920004e7ed9
R13: ffffc9000273f700 R14: ffffc9000273f6c8 R15: ffffffff8172d195
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 uevent_show+0x15a/0x310
 dev_attr_show+0x58/0xc0
 sysfs_kf_seq_show+0x310/0x490
 seq_read_iter+0x4ea/0xe10
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fe8116b6a
RSP: 002b:00007ffe7d002a48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055b6deaf5be0 RCX: 00007f0fe8116b6a
RDX: 0000000000001000 RSI: 000055b6deb3d350 RDI: 000000000000000c
RBP: 000055b6deaf5be0 R08: 000000000000000c R09: 0000000000000080
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffe7d002f28 R15: 000000000000000a
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g19409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=7935
rcu: rcu_preempt kthread starved for 10506 jiffies! g19409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I 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>
