TITLE: INFO: rcu detected stall in ext4_file_read_iter
ALT: stall in ext4_file_read_iter
TYPE: HANG

[  483.600289][    C1] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[  483.607580][    C1] rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l
[  483.615937][    C1] 	(detected by 1, t=10502 jiffies, g=49045, q=284)
[  483.622522][    C1] task:syz-executor.0  state:R  running task     stack:24880 pid:17688 ppid: 13379 flags:0x00004000
[  483.633869][    C1] Call Trace:
[  483.637152][    C1]  __schedule+0x911/0x21b0
[  483.651670][    C1]  preempt_schedule_irq+0x4e/0x90
[  483.656701][    C1]  irqentry_exit+0x7a/0xa0
[  483.661116][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  483.667102][    C1] RIP: 0010:lock_acquire+0x1ef/0x740
[  483.672397][    C1] Code: 50 a8 7e 83 f8 01 0f 85 ee 03 00 00 9c 58 f6 c4 02 0f 85 d9 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
[  483.692003][    C1] RSP: 0018:ffffc90002c0f098 EFLAGS: 00000206
[  483.698066][    C1] RAX: dffffc0000000000 RBX: 1ffff92000581e15 RCX: 000000005caa8f7c
[  483.706035][    C1] RDX: 1ffff1100236013d RSI: 0000000000000000 RDI: 0000000000000000
[  483.714002][    C1] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fa988a7
[  483.721969][    C1] R10: fffffbfff1f53114 R11: 0000000000000000 R12: 0000000000000002
[  483.729935][    C1] R13: ffffffff8bf74320 R14: 0000000000000000 R15: 0000000000000000
[  483.753445][    C1]  find_get_pages_range+0x11b/0x890
[  483.773673][    C1]  pagevec_lookup_range+0x32/0x70
[  483.778702][    C1]  clean_bdev_aliases+0x19d/0x830
[  483.827100][    C1]  __block_write_begin_int+0xa48/0x1770
[  483.854080][    C1]  block_page_mkwrite+0x21f/0x310
[  483.859113][    C1]  ext4_page_mkwrite+0xbdf/0x1a10
[  483.875868][    C1]  do_page_mkwrite+0x1a7/0x530
[  483.880638][    C1]  __handle_mm_fault+0x2baa/0x4f70
[  483.890713][    C1]  handle_mm_fault+0x1bc/0x7e0
[  483.895484][    C1]  do_user_addr_fault+0x483/0x1210
[  483.900608][    C1]  exc_page_fault+0x9e/0x180
[  483.905459][    C1]  asm_exc_page_fault+0x1e/0x30
[  483.910309][    C1] RIP: 0010:copy_user_generic_string+0x2c/0x40
[  483.916467][    C1] Code: cb 83 fa 08 72 27 89 f9 83 e1 07 74 15 83 e9 08 f7 d9 29 ca 8a 06 88 07 48 ff c6 48 ff c7 ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 <f3> 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 0f 1f 80 00 00 00 00 0f 01
[  483.936073][    C1] RSP: 0018:ffffc90002c0fa00 EFLAGS: 00050246
[  483.942141][    C1] RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000030
[  483.950110][    C1] RDX: 0000000000000000 RSI: ffff888032d9ae80 RDI: 000000002018f000
[  483.958085][    C1] RBP: 000000002018e180 R08: 0000000000000000 R09: ffff888032d9afff
[  483.966673][    C1] R10: ffffed10065b35ff R11: 0000000000000000 R12: ffff888032d9a000
[  483.974642][    C1] R13: 000000002018f180 R14: 0000000000000000 R15: 0000000000001000
[  483.982623][    C1]  copyout.part.0+0xe4/0x110
[  483.987217][    C1]  copy_page_to_iter+0x41b/0xee0
[  483.992161][    C1]  filemap_read+0x61e/0xe40
[  484.007972][    C1]  generic_file_read_iter+0x397/0x4f0
[  484.013358][    C1]  ext4_file_read_iter+0x1d4/0x5d0
[  484.018477][    C1]  new_sync_read+0x41e/0x6e0
[  484.036965][    C1]  vfs_read+0x35c/0x570
[  484.041125][    C1]  ksys_read+0x12d/0x250
[  484.055694][    C1]  do_syscall_64+0x2d/0x70
[  484.060117][    C1]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  484.066015][    C1] RIP: 0033:0x466459
[  484.069903][    C1] RSP: 002b:00007faf4cb38188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[  484.078316][    C1] RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459
[  484.086287][    C1] RDX: 00000000fffffe47 RSI: 0000000020000180 RDI: 0000000000000006
[  484.094254][    C1] RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
[  484.102222][    C1] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
[  484.110189][    C1] R13: 00007ffc561d590f R14: 00007faf4cb38300 R15: 0000000000022000
[  484.118175][    C1] task:kworker/u4:0    state:R  running task     stack:25072 pid:    9 ppid:     2 flags:0x00004000
[  484.128951][    C1] Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
[  484.136761][    C1] Call Trace:
[  484.140036][    C1]  __schedule+0x911/0x21b0
[  484.154524][    C1]  preempt_schedule_irq+0x4e/0x90
[  484.159552][    C1]  irqentry_exit+0x7a/0xa0
[  484.163967][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  484.169947][    C1] RIP: 0010:lock_acquire+0x1ef/0x740
[  484.175235][    C1] Code: 50 a8 7e 83 f8 01 0f 85 ee 03 00 00 9c 58 f6 c4 02 0f 85 d9 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
[  484.194842][    C1] RSP: 0018:ffffc90000ce7aa8 EFLAGS: 00000206
[  484.200908][    C1] RAX: dffffc0000000000 RBX: 1ffff9200019cf57 RCX: 00000000f9e69e84
[  484.208875][    C1] RDX: 1ffff1100222f13d RSI: 0000000000000000 RDI: 0000000000000000
[  484.216844][    C1] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fa988a7
[  484.224813][    C1] R10: fffffbfff1f53114 R11: 0000000000000000 R12: 0000000000000002
[  484.232780][    C1] R13: ffffffff8bf74320 R14: 0000000000000000 R15: 0000000000000000
[  484.261152][    C1]  batadv_iv_ogm_schedule_buff+0x5d0/0x1410
[  484.290571][    C1]  batadv_iv_send_outstanding_bat_ogm_packet+0x675/0x920
[  484.297605][    C1]  process_one_work+0x98d/0x1600
[  484.317896][    C1]  worker_thread+0x64c/0x1120
[  484.327786][    C1]  kthread+0x3b1/0x4a0
[  484.336972][    C1]  ret_from_fork+0x1f/0x30
[  484.341402][    C1] rcu: rcu_preempt kthread starved for 10500 jiffies! g49045 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
[  484.352595][    C1] rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
[  484.362554][    C1] rcu: RCU grace-period kthread stack dump:
[  484.368430][    C1] task:rcu_preempt     state:R  running task     stack:28872 pid:   14 ppid:     2 flags:0x00004000
[  484.379200][    C1] Call Trace:
[  484.382474][    C1]  __schedule+0x911/0x21b0
[  484.397567][    C1]  schedule+0xcf/0x270
[  484.401643][    C1]  schedule_timeout+0x14a/0x250
[  484.428092][    C1]  rcu_gp_kthread+0xd07/0x2250
[  484.468669][    C1]  kthread+0x3b1/0x4a0
[  484.477858][    C1]  ret_from_fork+0x1f/0x30
[  484.482286][    C1] rcu: Stack dump where RCU GP kthread last ran:
[  484.488597][    C1] NMI backtrace for cpu 1
[  484.492912][    C1] CPU: 1 PID: 17698 Comm: syz-executor.3 Not tainted 5.12.0-rc6-syzkaller #0
[  484.501670][    C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  484.511718][    C1] Call Trace:
[  484.514989][    C1]  <IRQ>
[  484.517830][    C1]  dump_stack+0x141/0x1d7
[  484.522164][    C1]  nmi_cpu_backtrace.cold+0x44/0xd7
[  484.532569][    C1]  nmi_trigger_cpumask_backtrace+0x1b3/0x230
[  484.538556][    C1]  rcu_check_gp_kthread_starvation+0x1c7/0x1e4
[  484.544710][    C1]  rcu_sched_clock_irq.cold+0x9a3/0x11dd
[  484.560418][    C1]  update_process_times+0x16d/0x200
[  484.565619][    C1]  tick_sched_handle+0x9b/0x180
[  484.570475][    C1]  tick_sched_timer+0x1b0/0x2d0
[  484.580876][    C1]  __hrtimer_run_queues+0x1c0/0xe40
[  484.598148][    C1]  hrtimer_interrupt+0x330/0xa00
[  484.603101][    C1]  __sysvec_apic_timer_interrupt+0x146/0x540
[  484.609095][    C1]  sysvec_apic_timer_interrupt+0x40/0xc0
[  484.614736][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  484.620721][    C1] RIP: 0010:unwind_next_frame+0x34f/0x1ce0
[  484.626527][    C1] Code: e8 96 f5 ff ff 49 89 c0 4d 85 c0 0f 84 39 02 00 00 4d 8d 78 04 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 0f b6 04 02 <4c> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 1e 09 00 00 41 0f b6 40
[  484.646136][    C1] RSP: 0000:ffffc90000dc07b8 EFLAGS: 00000216
[  484.652200][    C1] RAX: 0000000000000000 RBX: 1ffff920001b80ff RCX: ffffffff8902d429
[  484.660167][    C1] RDX: 1ffffffff1da0a8b RSI: ffffffff8ed05456 RDI: ffffffff8e33ff84
[  484.668140][    C1] RBP: 0000000000000001 R08: ffffffff8ed05456 R09: ffffffff8ed05456
[  484.676108][    C1] R10: fffff520001b811d R11: 0000000000084087 R12: ffffc90000dc08d8
[  484.684082][    C1] R13: ffffc90000dc08c5 R14: ffffc90000dc0890 R15: ffffffff8ed0545a
[  484.721433][    C1]  arch_stack_walk+0x7d/0xe0
[  484.735470][    C1]  stack_trace_save+0x8c/0xc0
[  484.745965][    C1]  kasan_save_stack+0x1b/0x40
[  484.911315][    C1]  kasan_set_track+0x1c/0x30
[  484.915906][    C1]  kasan_set_free_info+0x20/0x30
[  484.920847][    C1]  __kasan_slab_free+0xf5/0x130
[  484.925701][    C1]  slab_free_freelist_hook+0x92/0x210
[  484.931079][    C1]  kmem_cache_free+0x8a/0x740
[  484.945401][    C1]  kfree_skbmem+0xef/0x1b0
[  484.949820][    C1]  consume_skb+0xcf/0x160
[  484.954154][    C1]  mac80211_hwsim_tx_frame+0x157/0x1e0
[  484.959617][    C1]  mac80211_hwsim_beacon_tx+0x4ba/0x910
[  484.965172][    C1]  __iterate_interfaces+0x1e5/0x520
[  484.987891][    C1]  ieee80211_iterate_active_interfaces_atomic+0x8d/0x170
[  484.994935][    C1]  mac80211_hwsim_beacon+0xd5/0x1a0
[  485.000143][    C1]  __hrtimer_run_queues+0x609/0xe40
[  485.017405][    C1]  hrtimer_run_softirq+0x17b/0x360
[  485.022518][    C1]  __do_softirq+0x29b/0x9f6
[  485.027032][    C1]  irq_exit_rcu+0x134/0x200
[  485.031537][    C1]  sysvec_apic_timer_interrupt+0x93/0xc0
[  485.037168][    C1]  </IRQ>
[  485.040100][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  485.046084][    C1] RIP: 0010:preempt_schedule_irq+0x49/0x90
[  485.051893][    C1] Code: 55 53 65 48 8b 1c 25 00 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 72 e2 49 f8 e8 3d 8c 75 f8 fb bf 01 00 00 00 <e8> c2 d0 ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 b0 d0 49
[  485.071496][    C1] RSP: 0000:ffffc90002c5fe68 EFLAGS: 00000206
[  485.077566][    C1] RAX: 00000000005a35db RBX: ffff88801f359c40 RCX: 1ffffffff1b89bc9
[  485.085534][    C1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
[  485.093500][    C1] RBP: ffffed1003e6b388 R08: 0000000000000001 R09: 0000000000000001
[  485.101471][    C1] R10: ffffffff8179e058 R11: 0000000000000001 R12: 0000000000000000
[  485.109440][    C1] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  485.127658][    C1]  irqentry_exit+0x7a/0xa0
[  485.132075][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  485.138060][    C1] RIP: 0010:exit_to_user_mode_prepare+0x10e/0x250
[  485.144477][    C1] Code: f6 c4 02 0f 85 0f 01 00 00 65 48 8b 04 25 00 f0 01 00 48 8b 18 f7 c3 0e 30 02 00 0f 84 2f ff ff ff e8 e6 99 17 00 fb f6 c3 08 <74> bf e8 1b 00 a2 07 f6 c7 10 74 ba 48 89 ef e8 2e d6 32 00 f7 c3
[  485.164080][    C1] RSP: 0000:ffffc90002c5ff30 EFLAGS: 00000202
[  485.170146][    C1] RAX: 000000000023ebc1 RBX: 0000000000000008 RCX: 1ffffffff1b89bc9
[  485.178117][    C1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  485.186082][    C1] RBP: ffffc90002c5ff58 R08: 0000000000000001 R09: 0000000000000001
[  485.194051][    C1] R10: ffffffff8179e058 R11: 0000000000000001 R12: ffff88801f359c40
[  485.202021][    C1] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  485.221095][    C1]  irqentry_exit_to_user_mode+0x5/0x40
[  485.226556][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  485.232539][    C1] RIP: 0033:0x466459
[  485.236431][    C1] 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 bc ff ff ff f7 d8 64 89 01 48
[  485.256034][    C1] RSP: 002b:00007f74636b8188 EFLAGS: 00000246
[  485.262099][    C1] RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000466459
[  485.270065][    C1] RDX: 0000000020000000 RSI: 0000000000005452 RDI: 0000000000000003
[  485.278033][    C1] RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
[  485.285999][    C1] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
[  485.293968][    C1] R13: 00007ffc06f8e1df R14: 00007f74636b8300 R15: 0000000000022000
