INFO: task kworker/u4:5:1057 blocked for more than 143 seconds. Not tainted 6.3.0-syzkaller-09882-gcec24b8b6bb8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:26656 pid:1057 ppid:2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:5307 [inline] __schedule+0xc91/0x5770 kernel/sched/core.c:6625 schedule+0xde/0x1a0 kernel/sched/core.c:6701 schedule_timeout+0x276/0x2b0 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common+0x1ce/0x5c0 kernel/sched/completion.c:106 io_ring_exit_work+0x51d/0x14b0 io_uring/io_uring.c:3077 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c7962b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c795fb0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c796ec0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6545 2 locks held by kworker/u4:5/1057: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc9000522fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 2 locks held by kworker/u4:7/2898: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc9000bb37da8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 2 locks held by getty/4749: #0: ffff88802c432098 ( &tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015c02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 2 locks held by syz-executor.2/5031: #0: ffff88803a0f9800 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: iterate_dir+0xd1/0x6f0 fs/readdir.c:55 #1: ffff88802bd0a460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2184 [inline] #1: ffff88802bd0a460 (sb_writers#4){.+.+}-{0:0}, at: iterate_dir+0x45d/0x6f0 fs/readdir.c:70 3 locks held by syz-executor.4/1483: 5 locks held by syz-executor.1/1497: 1 lock held by syz-executor.3/1509: #0: ffff88803a3ad400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:771 [inline] #0: ffff88803a3ad400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_dio_read_iter fs/ext4/file.c:78 [inline] #0: ffff88803a3ad400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_file_read_iter+0x535/0x690 fs/ext4/file.c:145 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-syzkaller-09882-gcec24b8b6bb8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5292 Comm: kworker/u4:10 Not tainted 6.3.0-syzkaller-09882-gcec24b8b6bb8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:__lock_acquire+0x1727/0x5df0 kernel/locking/lockdep.c:5070 Code: f8 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 80 cc 50 91 e8 d1 8a 70 00 48 0f a3 1d 49 cb eb 0f <0f> 83 51 06 00 00 48 8d 1c 5b 48 c1 e3 06 48 81 c3 a0 d0 50 91 48 RSP: 0018:ffffc9000517f7a0 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 0000000000000614 RCX: ffffffff8165012f RDX: fffffbfff22a19a9 RSI: 0000000000000008 RDI: ffffffff9150cd40 RBP: 0000000000000003 R08: 0000000000000000 R09: ffffffff9150cd47 R10: fffffbfff22a19a8 R11: 0000000000000000 R12: ffff8880329ca8d8 R13: ffff8880329c9dc0 R14: 0000000000000000 R15: 4bd75d9941c1d1d9 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000202a7000 CR3: 0000000076ae6000 CR4: 0000000000350ef0 Call Trace: lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 folio_wake_bit+0x103/0x270 mm/filemap.c:1149 folio_wake mm/filemap.c:1184 [inline] folio_end_writeback+0x2a3/0x3b0 mm/filemap.c:1622 ext4_finish_bio+0x8bd/0x1090 fs/ext4/page-io.c:145 ext4_release_io_end+0x118/0x3b0 fs/ext4/page-io.c:160 ext4_end_io_end fs/ext4/page-io.c:194 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline] ext4_end_io_rsv_work+0x156/0x670 fs/ext4/page-io.c:273 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308