rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-....: (2 GPs behind) idle=7044/1/0x4000000000000000 softirq=71935/71935 fqs=10
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:        3          1            0
rcu: 	cputime:        0         99            0   ==> 28070(ms)
rcu: 	(detected by 0, t=10502 jiffies, g=66997, q=473 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5581 Comm: syz-executor 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:debug_smp_processor_id+0x0/0x20
Code: 80 ec e3 8f 4c 89 f6 e8 de d4 35 f9 e9 67 ff ff ff cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 c7 c7 20 17 6e 8c 48 c7 c6 60 17 6e 8c eb 1c 66 66
RSP: 0018:ffffc90000a16f78 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffffffff8205e7b1 RCX: ffff888111ddbc00
RDX: 00000000c1ee3112 RSI: ffffffff8e6f7641 RDI: ffffffff8c6e1780
RBP: 1ffff92000142e27 R08: ffffffff817811df R09: 0000000000000001
R10: ffffc90000a17150 R11: fffff52000142e2c R12: dffffc0000000000
R13: ffffffff817811df R14: ffffc90000a17100 R15: 1ffff92000142e20
FS:  00005555734ff540(0000) GS:ffff8882a7cab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc3ebfebc40 CR3: 0000000111b4e000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_is_watching+0x16/0xb0
 unwind_next_frame+0xbe/0x2550
 __unwind_start+0x514/0x660
 perf_callchain_kernel+0x2a5/0x6a0
 get_perf_callchain+0x25b/0x880
 perf_callchain+0x2df/0x390
 perf_prepare_sample+0x3b1/0x2270
 perf_event_output_forward+0x17d/0x480
 __perf_event_overflow+0x833/0xea0
 perf_swevent_event+0x438/0x810
 perf_tp_event+0x5fe/0x29d0
 perf_trace_run_bpf_submit+0xee/0x170
 perf_trace_lock_acquire+0x346/0x440
 lock_acquire+0x303/0x350
 _raw_spin_lock_irqsave+0x40/0x60
 debug_object_deactivate+0x9a/0x250
 __hrtimer_run_queues+0x239/0xa10
 hrtimer_interrupt+0x4cd/0xaa0
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:perf_swevent_event+0x75f/0x810
Code: e6 00 02 00 00 75 51 e8 6f 8b c1 ff 4d 89 fe 4d 85 e4 75 07 e8 62 8b c1 ff eb 06 e8 5b 8b c1 ff fb 48 c7 44 24 40 0e 36 e0 45 <4a> c7 04 33 00 00 00 00 65 48 8b 05 a9 5b 90 12 48 3b 84 24 80 00
RSP: 0018:ffffc90000a18020 EFLAGS: 00000246
RAX: ffffffff8206f465 RBX: 1ffff9200014300c RCX: ffff888111ddbc00
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: ffffc90000a180f0 R08: 0000000000000100 R09: 1ffffffff22f582f
R10: dffffc0000000000 R11: fffffbfff22f5830 R12: 0000000000000200
R13: ffffc90000a181c8 R14: dffffc0000000000 R15: dffffc0000000000
 perf_tp_event+0x5fe/0x29d0
 perf_trace_run_bpf_submit+0xee/0x170
 perf_trace_lock_acquire+0x346/0x440
 lock_acquire+0x303/0x350
 unwind_next_frame+0xac/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x354/0x610
 __alloc_skb+0x27a/0x7a0
 ndisc_alloc_skb+0xa0/0x480
 ndisc_send_rs+0x288/0x6b0
 addrconf_rs_timer+0x2d2/0x6c0
 call_timer_fn+0x18d/0x5f0
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x226/0x860
 __irq_exit_rcu+0xcb/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:strlen+0x2e/0x70
Code: 41 57 41 56 41 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 42 0f b6 04 30 <84> c0 75 11 48 ff c3 49 8d 47 01 42 80 7c 3f 01 00 75 de eb 19 89
RSP: 0018:ffffc90004c46b78 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: ffffffff8c0e45a5 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8fd5ce60 RDI: ffffffff8c0e45a0
RBP: ffffc90004c46c88 R08: 0000000000000002 R09: 0000000000000000
R10: ffffc90004c46e38 R11: ffffffff81b334c0 R12: ffffffff8fc289e0
R13: 0000000000000002 R14: dffffc0000000000 R15: 0000000000000004
 perf_trace_lock_acquire+0xdf/0x440
 lock_acquire+0x303/0x350
 unwind_next_frame+0xac/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0xee/0x8b0
 mm_destroy_sched+0x74/0xc0
 __mmdrop+0x93/0x4d0
 finish_task_switch+0x69a/0xc60
 __schedule+0x17e3/0x58f0
 schedule+0x164/0x2b0
 schedule_hrtimeout_range_clock+0x15b/0x330
 poll_schedule_timeout+0xd0/0x1a0
 do_select+0xc5b/0x17f0
 core_sys_select+0x86d/0xb40
 __se_sys_pselect6+0x267/0x320
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb78e7596d7
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc4a82d6f0 EFLAGS: 00000202 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00005555734ff540 RCX: 00007fb78e7596d7
RDX: 0000000000000000 RSI: 00007ffc4a82d810 RDI: 000000000000001c
RBP: 00007ffc4a82dc70 R08: 00007ffc4a82d730 R09: 00007ffc4a82d740
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc4a82dab0
R13: 00007ffc4a82d8a0 R14: 585858582e7a7973 R15: 00007ffc4a82dce0
 </TASK>
rcu: rcu_preempt kthread starved for 2807 jiffies! g66997 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:26848 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: 1108 Comm: kworker/u9:6 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+0x1132/0x1500
Code: 78 44 8b 2b 44 89 ee 83 e6 01 31 ff e8 f7 4d 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 e2 48 0c 00 eb 35 f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 c8 48 0c 00
RSP: 0018:ffffc900066d6120 EFLAGS: 00000293
RAX: ffffffff81bc36f8 RBX: ffff88823c6414c8 RCX: ffff88810bd88000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900066d6270 R08: ffff888118116d87 R09: 1ffff11023022db0
R10: dffffc0000000000 R11: ffffffff8179fc60 R12: 1ffff110478c8299
R13: dffffc0000000000 R14: 1ffff110217b12b3 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88818c4ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f43e5bf0158 CR3: 000000011a54a000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
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
 mpage_process_page_bufs+0x6bd/0x8a0
 mpage_prepare_extent_to_map+0xf92/0x1890
 ext4_do_writepages+0xb8a/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>
