syzbot

INFO: task udevd:3524 blocked for more than 430 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:0     pid:3524  tgid:3524  ppid:3142   task_flags:0x400140 flags:0x00000011
Call trace:
 __switch_to+0x200/0x500 arch/arm64/kernel/process.c:742 (T)
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xcc4/0x3294 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 schedule+0xcc/0x348 kernel/sched/core.c:7005
 io_schedule+0xac/0x120 kernel/sched/core.c:7832
 folio_wait_bit_common+0x2b0/0x650 mm/filemap.c:1323
 folio_put_wait_locked mm/filemap.c:1492 [inline]
 do_read_cache_folio+0x238/0x364 mm/filemap.c:4083
 read_cache_folio+0x44/0x6c mm/filemap.c:4133
 read_mapping_folio include/linux/pagemap.h:1028 [inline]
 read_part_sector+0xa4/0x5f8 block/partitions/core.c:723
 msdos_partition+0xec/0x1f20 block/partitions/msdos.c:592
 check_partition block/partitions/core.c:142 [inline]
 blk_add_partitions block/partitions/core.c:590 [inline]
 bdev_disk_changed+0x520/0x1028 block/partitions/core.c:694
 blkdev_get_whole+0x144/0x1f0 block/bdev.c:764
 bdev_open+0x1d4/0xa70 block/bdev.c:973
 blkdev_open+0x270/0x3f0 block/fops.c:697
 do_dentry_open+0x388/0x10e4 fs/open.c:949
 vfs_open+0x5c/0x2fc fs/open.c:1081
 do_open fs/namei.c:4671 [inline]
 path_openat+0x1734/0x2654 fs/namei.c:4830
 do_file_open+0x18c/0x37c fs/namei.c:4859
 do_sys_openat2+0xdc/0x184 fs/open.c:1366
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __arm64_sys_openat+0x130/0x1d0 fs/open.c:1383
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x70/0x260 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x29c arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Showing all locks held in the system:
2 locks held by pr/ttyAMA-1/31:
1 lock held by khungtaskd/32:
 #0: ffff800087752420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x198 kernel/locking/lockdep.c:6771
3 locks held by udevd/3142:
2 locks held by getty/3267:
 #0: ffff000016b510a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80008db3b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x420/0xee0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/3322:
1 lock held by udevd/3524:
 #0: ffff000014b3a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x2b8/0xa70 block/bdev.c:961
1 lock held by syz-executor/6131:

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