syzbot

INFO: task syz.1.989:7477 blocked for more than 143 seconds.
      Not tainted 6.1.147-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.989       state:D stack:0     pid:7477  ppid:4320   flags:0x00000009
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xddc/0x1b18 kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 io_schedule+0x84/0x154 kernel/sched/core.c:8797
 folio_wait_bit_common+0x56c/0x9c4 mm/filemap.c:1324
 __folio_lock+0x2c/0x3c mm/filemap.c:1687
 folio_lock include/linux/pagemap.h:974 [inline]
 __migrate_folio_unmap mm/migrate.c:1088 [inline]
 migrate_folio_unmap mm/migrate.c:1270 [inline]
 migrate_pages_batch mm/migrate.c:1635 [inline]
 migrate_pages+0x203c/0x3bbc mm/migrate.c:1843
 compact_zone+0x2274/0x3c94 mm/compaction.c:2414
 compact_node+0x1d8/0x370 mm/compaction.c:2691
 compact_nodes mm/compaction.c:2707 [inline]
 sysctl_compaction_handler+0x88/0x108 mm/compaction.c:2749
 proc_sys_call_handler+0x3fc/0x69c fs/proc/proc_sysctl.c:602
 proc_sys_write+0x2c/0x3c fs/proc/proc_sysctl.c:628
 do_iter_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x530/0x91c fs/read_write.c:861
 vfs_iter_write+0x88/0xac fs/read_write.c:902
 iter_file_splice_write+0x500/0xa18 fs/splice.c:685
 do_splice_from fs/splice.c:763 [inline]
 direct_splice_actor+0xe4/0x134 fs/splice.c:950
 splice_direct_to_actor+0x3b4/0x978 fs/splice.c:896
 do_splice_direct+0x158/0x244 fs/splice.c:1002
 do_sendfile+0x458/0xc88 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __arm64_sys_sendfile64+0x130/0x360 fs/read_write.c:1309
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015287770 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015287f90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffff800015286e00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by getty/4081:
 #0: ffff0000d6946098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff8000207ce2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2ec/0xf9c drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4331:
1 lock held by udevd/5292:
 #0: ffff0000ceb9a4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x118/0x8cc block/bdev.c:815
1 lock held by syz.1.989/7477:
 #0: ffff0000d7f9c460 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x43c/0xc88 fs/read_write.c:1254
1 lock held by syz.2.1133/7859:
 #0: ffff0000cae860e0 (&type->s_umount_key#72/1){+.+.}-{3:3}, at: alloc_super+0x1a4/0x804 fs/super.c:228
1 lock held by syz.3.2274/11736:

=============================================