rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=93d4/1/0x4000000000000000 softirq=19798/19798 fqs=17
rcu: 	(detected by 1, t=10502 jiffies, g=13093, q=300 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6746 Comm: syz.0.200 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:preempt_count_add+0x0/0x1a0
Code: c1 7c 97 48 8b 3c 24 e8 8e aa 93 00 eb 8c e9 f1 fe ff ff 0f 1f 80 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 49 bf 00 00 00 00 00 fc ff df 48 c7 c0
RSP: 0000:ffffc9000387f7b8 EFLAGS: 00000046
RAX: f3f3f300f1f1f1f1 RBX: ffff88804b027a80 RCX: ffff888108d01cc0
RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc9000387f858 R08: ffff88804b027a83 R09: 1ffff11009604f50
R10: dffffc0000000000 R11: ffffed1009604f51 R12: dffffc0000000000
R13: ffff88804b027b00 R14: 0000000000000802 R15: 1ffff9200070fef8
FS:  00007f31de4126c0(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000010db38000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 _raw_spin_lock_irqsave+0x8c/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+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x7f31dd58eba9
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:00007f31de412038 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f31dd7d5fa0 RCX: 00007f31dd58eba9
RDX: 0000000000000001 RSI: 0000000000002402 RDI: 0000000000000004
RBP: 00007f31dd611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31dd7d6038 R14: 00007f31dd7d5fa0 R15: 00007fffc6ff1f48
 </TASK>
rcu: rcu_preempt kthread starved for 10468 jiffies! g13093 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:27224 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: 36 Comm: kworker/u10:1 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:ffffc900006ae3a0 EFLAGS: 00000293
RAX: ffffffff81b4621b RBX: 1ffff11009608341 RCX: ffff8881001d8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900006ae520 R08: ffff888023658a07 R09: 1ffff110046cb140
R10: dffffc0000000000 R11: ffffffff8174be80 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c389b5c CR3: 000000002850e000 CR4: 00000000000006f0
DR0: 0000200000000300 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
 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
 ext4_do_writepages+0x1d43/0x4610
 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>
