syzbot

INFO: task kworker/u4:1:136 blocked for more than 143 seconds.
      Not tainted 5.15.152-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:    0 pid:  136 ppid:     2 flags:0x00000008
Workqueue: writeback wb_workfn (flush-7:0)
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
 __mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
 jfs_commit_inode+0x1d4/0x4f8 fs/jfs/inode.c:102
 jfs_write_inode+0x128/0x200 fs/jfs/inode.c:132
 write_inode fs/fs-writeback.c:1495 [inline]
 __writeback_single_inode+0x584/0x13a4 fs/fs-writeback.c:1705
 writeback_sb_inodes+0x94c/0x1654 fs/fs-writeback.c:1930
 __writeback_inodes_wb+0x110/0x39c fs/fs-writeback.c:2001
 wb_writeback+0x410/0xfc8 fs/fs-writeback.c:2106
 wb_check_background_flush fs/fs-writeback.c:2172 [inline]
 wb_do_writeback fs/fs-writeback.c:2260 [inline]
 wb_workfn+0xc44/0x1070 fs/fs-writeback.c:2288
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:319
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014ae14a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
4 locks held by kworker/u4:1/136:
 #0: ffff0000c21c8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff80001a357c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
 #2: ffff0000c9ca20e0 (&type->s_umount_key#41){.+.+}-{3:3}, at: trylock_super+0x28/0xf8 fs/super.c:418
 #3: ffff0000df503008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1d4/0x4f8 fs/jfs/inode.c:102
2 locks held by getty/3723:
 #0: ffff0000d339f098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001a12b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
4 locks held by syz-executor171/3984:

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