rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=e6a4/1/0x4000000000000000 softirq=63799/63799 fqs=10
rcu: 	(detected by 1, t=10502 jiffies, g=49225, q=56 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12927 Comm: syz.5.1735 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:hrtimer_try_to_cancel+0x1e1/0x420
Code: 18 eb e6 89 d9 80 e1 07 80 c1 03 38 c1 7c ea 48 89 df e8 42 3d 76 00 eb e0 e8 2b 1a 12 00 e9 ce fe ff ff e8 21 1a 12 00 eb 05 <e8> 1a 1a 12 00 4c 8b 64 24 08 48 8b 44 24 10 42 80 3c 30 00 74 08
RSP: 0018:ffffc90000007928 EFLAGS: 00000046
RAX: ffff88810c334628 RBX: ffff88804b027b10 RCX: 0000000000010000
RDX: ffff88802bd11cc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000ad3452 R08: ffff88804b027a83 R09: 1ffff11009604f50
R10: dffffc0000000000 R11: ffffed1009604f51 R12: 1ffff11009604f62
R13: ffff88804b027b48 R14: dffffc0000000000 R15: ffff88804b027b00
FS:  00007f18745e76c0(0000) GS:ffff8880b8611000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000011c0 CR3: 00000000284ac000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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 6b d0 49 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> 23 75 12 f6 65 8b 05 6c 51 23 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900045bfaa0 EFLAGS: 00000206
RAX: 02c78b813221e700 RBX: 0000000000000a02 RCX: 02c78b813221e700
RDX: 0000000000000000 RSI: ffffffff8d9baef1 RDI: 0000000000000001
RBP: ffffc900045bfb28 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff8880217fc390 R15: 1ffff920008b7f54
 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: 0033:0x7f187378ec29
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:00007f18745e70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f18739d5fa8 RCX: 00007f187378ec29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f18739d5fac
RBP: 00007f18739d5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f18739d6038 R14: 00007ffdd954c6c0 R15: 00007ffdd954c7a8
 </TASK>
rcu: rcu_preempt kthread starved for 10482 jiffies! g49225 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:26664 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: 1 UID: 0 PID: 3544 Comm: kworker/u10:4 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
Workqueue: writeback wb_workfn (flush-8:0)
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:ffffc90003e5e060 EFLAGS: 00000293
RAX: ffffffff81b4665b RBX: 1ffff11009608341 RCX: ffff88810df51cc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003e5e1e0 R08: ffff8881085e6ac7 R09: 1ffff110210bcd58
R10: dffffc0000000000 R11: ffffffff8174be80 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f18745a4fc8 CR3: 00000000284ac000 CR4: 00000000000006f0
DR0: 0000200000000440 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 ptep_clear_flush+0x120/0x170
 page_vma_mkclean_one+0x406/0x740
 page_mkclean_one+0x1c0/0x280
 __rmap_walk_file+0x467/0x620
 folio_mkclean+0x297/0x390
 folio_clear_dirty_for_io+0x1fa/0x8c0
 mpage_submit_folio+0x86/0x2b0
 mpage_process_page_bufs+0x6d5/0x8e0
 mpage_prepare_extent_to_map+0xe6c/0x16e0
 ext4_do_writepages+0xba0/0x4610
 ext4_writepages+0x205/0x350
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x145/0xff0
 writeback_sb_inodes+0x6c7/0x1010
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x44f/0xaf0
 wb_workfn+0xaef/0xef0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
