rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=b52c/1/0x4000000000000000 softirq=86701/86707 fqs=131
rcu: 	(detected by 1, t=10502 jiffies, g=79585, q=189 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 19285 Comm: syz.9.5605 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:check_preemption_disabled+0x47/0x120
Code: 07 65 8b 0d cb 44 41 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d ab 44 41 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e <41> 5f 5d e9 d1 c8 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7
RSP: 0018:ffffc90000007c00 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 020a086214023600
RDX: 0000000000000001 RSI: ffffffff8dbcfb8f RDI: ffffffff8c035c00
RBP: ffffc90000007d08 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f70 R12: dffffc0000000000
R13: ffffffff81add05d R14: ffffffff99f534b8 R15: ffff88803fbe0000
FS:  0000555569a3c500(0000) GS:ffff8880b83f1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33121ff8 CR3: 000000000e138000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lock_release+0xbc/0x3e0
 _raw_spin_unlock_irqrestore+0x70/0x110
 debug_deactivate+0x1d/0x200
 __hrtimer_run_queues+0x2b0/0xc60
 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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 db a1 25 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900089874b8 EFLAGS: 00000206
RAX: 020a086214023600 RBX: 0000000000000000 RCX: 020a086214023600
RDX: 0000000000000000 RSI: ffffffff8ddaba42 RDI: ffffffff8c035c00
RBP: ffffffff822ecb2a R08: 0000000000000000 R09: ffffffff822ecb2a
R10: dffffc0000000000 R11: fffff940001d2f41 R12: 0000000000000002
R13: ffffffff8e33c5e0 R14: 0000000000000000 R15: 0000000000000246
 pfn_valid+0xd6/0x490
 page_table_check_clear+0x21/0x700
 unmap_page_range+0x344b/0x4370
 unmap_vmas+0x399/0x580
 exit_mmap+0x240/0xb40
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f455b98ebe9
Code: Unable to access opcode bytes at 0x7f455b98ebbf.
RSP: 002b:00007fffb06291e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f455b98ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffb062924c R08: 00000005b06292df R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000b8
R13: 00000000000927c0 R14: 000000000007306d R15: 00007fffb06292a0
 </TASK>
rcu: rcu_preempt kthread starved for 10240 jiffies! g79585 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:27256 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+0x47f/0x820
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 4265 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 16 77 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 c1 72 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 a5 72
RSP: 0018:ffffc900206fe040 EFLAGS: 00000293
RAX: ffffffff81b437db RBX: 1ffff11009608355 RCX: ffff88810a15d700
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900206fe1c0 R08: ffff888109d54a87 R09: 1ffff110213aa950
R10: dffffc0000000000 R11: ffffffff8175a7c0 R12: ffff88804b041aa8
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a39f1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c39ee44 CR3: 0000000111c9a000 CR4: 00000000000006f0
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+0x1f5/0x880
 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+0x47f/0x820
 ret_from_fork_asm+0x1a/0x30
 </TASK>
