rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=b18c/1/0x4000000000000000 softirq=253747/253748 fqs=269
rcu: 	(detected by 0, t=10505 jiffies, g=242921, q=798 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16178 Comm: syz.2.17425 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:advance_sched+0xef/0xc80
Code: f7 01 89 c3 31 ff 89 c6 e8 7e 79 db f7 85 db 74 28 49 8d 7e c0 be ff ff ff ff e8 ac 74 f7 01 89 c3 31 ff 89 c6 e8 61 79 db f7 <85> db 0f 84 dd 06 00 00 e8 54 74 db f7 eb 05 e8 4d 74 db f7 4c 89
RSP: 0000:ffffc90000a18cf8 EFLAGS: 00000002
RAX: ffffffff89ec424f RBX: 0000000000000001 RCX: ffff888172d2da00
RDX: 0000000001000001 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff8881719e5300 R08: 0000000001000001 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000143190 R12: 0000000000000002
R13: ffff8881719e5000 R14: ffff8881719e5300 R15: dffffc0000000000
FS:  0000555569479500(0000) GS:ffff8882a8cda000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5b41e16618 CR3: 00000001a7d18000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __hrtimer_run_queues+0x3bc/0xa10
 hrtimer_interrupt+0x4cd/0xaa0
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:seqcount_lockdep_reader_access+0x9d/0xc0
Code: 79 ff 48 83 c4 08 48 89 df 4c 89 f6 e8 9c 38 79 ff e8 57 ea a5 ff 9c 58 a9 00 02 00 00 75 15 41 f7 c7 00 02 00 00 74 01 fb 5b <41> 5e 41 5f c3 cc cc cc cc cc e8 c4 a2 b9 09 41 f7 c7 00 02 00 00
RSP: 0000:ffffc900040a75d8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: ffff88823fff8100 RCX: 0000000000000046
RDX: 0000000000000007 RSI: ffffffff8e473d0e RDI: ffffffff8c6d9380
RBP: ffffea00068a1d40 R08: ffffffff907a137f R09: 1ffffffff20f426f
R10: dffffc0000000000 R11: fffffbfff20f4270 R12: ffff88823fff81d0
R13: 0000000000000881 R14: ffffffff822a0aae R15: 0000000000000a02
 bad_range+0x8e/0x2a0
 get_page_from_freelist+0x21f4/0x2280
 __alloc_frozen_pages_noprof+0x217/0x5a0
 alloc_pages_mpol+0x21e/0x390
 folio_alloc_mpol_noprof+0x39/0x160
 vma_alloc_folio_noprof+0xe1/0x1e0
 do_wp_page+0x117d/0x4b80
 handle_mm_fault+0x15d7/0x3750
 do_user_addr_fault+0xa4f/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f5b41a517fc
Code: 23 83 c0 01 44 39 d0 75 dc 48 89 f0 25 ff 1f 00 00 49 89 34 c1 41 88 3c 00 31 c0 c3 66 90 41 38 3c 10 74 0b 41 88 3c 10 31 c0 <49> 89 34 d1 c3 b8 01 00 00 00 c3 66 0f 1f 84 00 00 00 00 00 48 83
RSP: 002b:00007ffcdd08a038 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff84e088c3 RCX: 0000000000000000
RDX: 00000000000008c3 RSI: ffffffff84e088c3 RDI: 0000000000000000
RBP: 0000000000000039 R08: 00007f5b41e10000 R09: 00007f5b41e12000
R10: 0000000084e088c7 R11: 0000000000000000 R12: 00007f5b41e26038
R13: 0000000000000058 R14: ffffffff84e088c3 R15: 00007f5b42955720
 </TASK>
rcu: rcu_preempt kthread starved for 9160 jiffies! g242921 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27696 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x38b/0x480
 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: 19511 Comm: kworker/u9:25 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0x61e/0x1500
Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 51 51 0c 00 41 83 e7 01 75 07 e8 46 4c 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01
RSP: 0018:ffffc90009106460 EFLAGS: 00000293
RAX: ffffffff81bb6a8e RBX: ffff88823c6414c8 RCX: ffff88811d149e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900091065b0 R08: ffff88811d14b39f R09: 1ffff11023a29673
R10: dffffc0000000000 R11: ffffffff8179dcb0 R12: 1ffff110478c8299
R13: 0000000000000001 R14: ffff88823c6414c0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88818d6da000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f324edef2f8 CR3: 000000000eb48000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 flush_tlb_mm_range+0x8ff/0x1090
 ptep_clear_flush+0x120/0x170
 page_vma_mkclean_one+0x4b9/0x840
 page_mkclean_one+0x20c/0x2e0
 __rmap_walk_file+0x4cd/0x6a0
 folio_mkclean+0x2d5/0x3f0
 folio_clear_dirty_for_io+0x190/0x820
 mpage_submit_folio+0x83/0x2a0
 ext4_do_writepages+0x203d/0x4770
 ext4_writepages+0x241/0x3b0
 do_writepages+0x338/0x560
 __writeback_single_inode+0x136/0x1220
 writeback_sb_inodes+0x9de/0x1b00
 __writeback_inodes_wb+0x114/0x240
 wb_writeback+0x42f/0xad0
 wb_workfn+0xc92/0x10f0
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
