rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=c1cc/1/0x4000000000000000 softirq=87064/87066 fqs=0
rcu: 	(t=15455 jiffies g=65865 q=245 ncpus=2)
rcu: rcu_preempt kthread starved for 15455 jiffies! g65865 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: kworker/u9:1 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+0xfcf/0x13d0
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 fa fc 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 a5 f8 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 8a f8 0b
RSP: 0018:ffffc90000a76140 EFLAGS: 00000293
RAX: ffffffff81b9d866 RBX: ffff88812103c148 RCX: ffff888103ad8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000a76280 R08: ffff888121024047 R09: 1ffff11024204808
R10: dffffc0000000000 R11: ffffffff81790290 R12: 1ffff110478c8169
R13: dffffc0000000000 R14: ffff88823c640b48 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88818dc14000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056307292c8b8 CR3: 00000001115d7000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 kvm_flush_tlb_multi+0x2b4/0x320
 flush_tlb_mm_range+0x5c3/0x10b0
 ptep_clear_flush+0x120/0x170
 page_vma_mkclean_one+0x438/0x780
 page_mkclean_one+0x1d8/0x2b0
 __rmap_walk_file+0x467/0x620
 folio_mkclean+0x2bb/0x3d0
 folio_clear_dirty_for_io+0x1a5/0x710
 mpage_submit_folio+0x86/0x2b0
 mpage_process_page_bufs+0x6d5/0x8e0
 mpage_prepare_extent_to_map+0xe1b/0x16f0
 ext4_do_writepages+0xbac/0x4670
 ext4_writepages+0x241/0x3b0
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x133/0x10e0
 writeback_sb_inodes+0x979/0x19d0
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x459/0xb00
 wb_workfn+0xb12/0xf10
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
CPU: 1 UID: 0 PID: 13046 Comm: syz.0.2053 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_schedule_irq+0x48/0xa0
Code: 49 be 00 00 00 00 00 fc ff df eb 09 48 f7 03 10 00 00 00 74 53 bf 01 00 00 00 e8 33 19 da f5 e8 6e 23 14 f6 fb bf 01 00 00 00 <e8> 13 a3 ff ff 9c 58 fa a9 00 02 00 00 74 05 e8 34 25 14 f6 bf 01
RSP: 0018:ffffc90003aa74c0 EFLAGS: 00000202
RAX: 00000000002bf6f7 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000007 RSI: ffffffff8dfd7eb5 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff903380f7 R09: 1ffffffff206701e
R10: dffffc0000000000 R11: fffffbfff206701f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fed3eec96c0(0000) GS:ffff8882a9214000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000010bbb6000 CR4: 0000000000352ef0
DR0: fffffffffffffff3 DR1: 0000000000008000 DR2: 0000000000000002
DR3: 0000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 irqentry_exit+0x14f/0x730
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0010:vcpu_run+0x965/0x7860
Code: 42 80 3c 38 00 74 08 4c 89 e7 e8 d6 30 e9 00 49 8b 1c 24 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 5c 32 00 00 0f b6 1b <31> ff 89 de e8 82 f8 7d 00 85 db 74 50 4c 89 e8 48 c1 e8 03 42 80
RSP: 0018:ffffc90003aa75e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90008511000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90003aa79b0 R08: ffff888176dca9ff R09: 1ffff1102edb953f
R10: dffffc0000000000 R11: ffffed102edb9540 R12: ffff888176dcaa90
R13: ffff888176dca9c0 R14: ffff888176dca9f8 R15: dffffc0000000000
 kvm_arch_vcpu_ioctl_run+0x11e6/0x20d0
 kvm_vcpu_ioctl+0xa62/0xfd0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fed3df9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fed3eec9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fed3e215fa0 RCX: 00007fed3df9cdd9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 000000000000000c
RBP: 00007fed3e032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fed3e216038 R14: 00007fed3e215fa0 R15: 00007fffd66fdfb8
 </TASK>
