syzbot

INFO: t
INFO: task syz-executor:6537 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:6537  tgid:6537  ppid:1      task_flags:0x400940 flags:0x00000011
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 io_schedule+0x84/0xf0 kernel/sched/core.c:7903
 folio_wait_bit_common+0x56c/0x9e0 mm/filemap.c:1317
 folio_wait_bit+0x30/0x40 mm/filemap.c:1456
 folio_wait_writeback+0x9c/0x100 mm/page-writeback.c:3124
 shrink_folio_list+0x3524/0x431c mm/vmscan.c:1264
 shrink_inactive_list mm/vmscan.c:2050 [inline]
 shrink_list mm/vmscan.c:2287 [inline]
 shrink_lruvec+0x1114/0x2248 mm/vmscan.c:5849
 shrink_node_memcgs mm/vmscan.c:6051 [inline]
 shrink_node+0xe08/0x22ac mm/vmscan.c:6092
 shrink_zones mm/vmscan.c:6336 [inline]
 do_try_to_free_pages+0x55c/0x1440 mm/vmscan.c:6398
 try_to_free_mem_cgroup_pages+0x2ec/0x9a4 mm/vmscan.c:6726
 try_charge_memcg+0x70c/0xea0 mm/memcontrol.c:2357
 try_charge mm/memcontrol.c:2499 [inline]
 charge_memcg+0xa0/0x184 mm/memcontrol.c:4702
 mem_cgroup_swapin_charge_folio+0x290/0x3f0 mm/memcontrol.c:4788
 __read_swap_cache_async+0x24c/0x4e4 mm/swap_state.c:441
 swap_vma_readahead mm/swap_state.c:762 [inline]
 swapin_readahead+0x6cc/0xb78 mm/swap_state.c:810
 do_swap_page+0x498/0x4794 mm/memory.c:4586
 handle_pte_fault mm/memory.c:6055 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0xd40/0x4d34 mm/memory.c:6364
 do_page_fault+0x410/0x13cc arch/arm64/mm/fault.c:653
 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:789
 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:929
 el0_da+0x64/0x164 arch/arm64/kernel/entry-common.c:697
 el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:901
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
INFO: task kmmpd-loop2:6771 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop2     state:D stack:0     pid:6771  tgid:6771  ppid:2      task_flags:0x208040 flags:0x00000010
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 io_schedule+0x84/0xf0 kernel/sched/core.c:7903
 bit_wait_io+0x1c/0xac kernel/sched/wait_bit.c:250
 __wait_on_bit kernel/sched/wait_bit.c:52 [inline]
 out_of_line_wait_on_bit+0x158/0x1f0 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 __wait_on_buffer+0x6c/0x7c fs/buffer.c:123
 wait_on_buffer include/linux/buffer_head.h:420 [inline]
 write_mmp_block_thawed+0x208/0x2dc fs/ext4/mmp.c:52
 write_mmp_block+0x1d0/0x5e0 fs/ext4/mmp.c:67
 kmmpd+0x2ec/0x9b8 fs/ext4/mmp.c:178
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/32:
 #0: ffff80008f9c9360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
2 locks held by pr/ttyAMA-1/43:
3 locks held by kworker/u8:9/4547:
 #0: ffff0000d4574148 ((wq_completion)loop2){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3210
 #1: ffff8000a00c7bc0 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3210
 #2: ffff0000cfa73080 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
 #2: ffff0000cfa73080 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: shmem_file_write_iter+0x80/0x134 mm/shmem.c:3518
2 locks held by getty/6315:
 #0: ffff0000d309f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009bbde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/6537:
 #0: ffff0000edad86c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x170/0x37c mm/mmap_lock.c:147
1 lock held by kmmpd-loop2/6771:
 #0: ffff0000c88c4428 (sb_writers#3){.+.+}-{0:0}, at: kmmpd+0x2ec/0x9b8 fs/ext4/mmp.c:178

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