INFO: task kworker/u4:19:4249 blocked for more than 143 seconds. Not tainted 6.8.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:19 state:D stack:19800 pid:4249 tgid:4249 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x177f/0x49a0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6874 rwsem_down_write_slowpath+0xeea/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1ae/0x200 kernel/locking/rwsem.c:1306 f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 f2fs_write_inode+0x3f0/0x470 fs/f2fs/inode.c:794 write_inode fs/fs-writeback.c:1473 [inline] __writeback_single_inode+0x69f/0xfd0 fs/fs-writeback.c:1690 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1987 wb_writeback+0x461/0xc80 fs/fs-writeback.c:2094 wb_check_old_data_flush fs/fs-writeback.c:2198 [inline] wb_do_writeback fs/fs-writeback.c:2251 [inline] wb_workfn+0xb7c/0xfb0 fs/fs-writeback.c:2279 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by kworker/u4:2/42: #0: ffff888014c79538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c79538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90000b2fd20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90000b2fd20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 2 locks held by udevd/4510: 2 locks held by getty/4808: #0: ffff88802a8930a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 4 locks held by kworker/u4:19/4249: #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000f887d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000f887d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff88802b3e00e0 (&type->s_umount_key#55){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff88802ebbd2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff88802ebbd2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 4 locks held by kworker/u4:1/20418: #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000367fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000367fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff88808758c0e0 (&type->s_umount_key#55){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff8880875a12a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff8880875a12a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 2 locks held by kworker/0:3/4428: #0: ffff888014c7a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c7a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000300fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000300fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 2 locks held by kworker/u4:3/11189: 5 locks held by syz-executor.3/12637: 5 locks held by syz-executor.2/12757: 4 locks held by kworker/u4:4/12963: #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90013227d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90013227d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff88803526a0e0 (&type->s_umount_key#55){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff888046c9d2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff888046c9d2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 6 locks held by syz-executor.1/13275: 1 lock held by udevd/13660: #0: ffff88801d09fc40 (mapping.invalidate_lock#2){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:859 [inline] #0: ffff88801d09fc40 (mapping.invalidate_lock#2){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xf1/0x7c0 mm/readahead.c:225 2 locks held by syz-executor.1/13794: 2 locks held by syz-executor.2/13802: 2 locks held by dhcpcd/13806: #0: ffff888035623810 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff888035623810 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff888035623810 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1421 #1: ffffffff8e136578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8e136578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:995 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13817 Comm: syz-executor.3 Not tainted 6.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0033:0x7fb5b7a29830 Code: 49 8b 47 10 48 39 f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 <49> 89 c1 49 29 f1 47 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b RSP: 002b:00007fb5b87eb530 EFLAGS: 00000202 RAX: 0000000000f0d765 RBX: 00007fb5b87eb5d0 RCX: 000000000000005e RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007fb5b87eb670 RBP: 0000000000000102 R08: 00007fb5ae000000 R09: 0000000000000000 R10: 0000000000000000 R11: 00007fb5b87eb5e0 R12: 0000000000000001 R13: 00007fb5b7aecd00 R14: 0000000000000000 R15: 00007fb5b87eb670 FS: 00007fb5b87ec6c0 GS: 0000000000000000