INFO: task kworker/u4:8:2887 blocked for more than 143 seconds. Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:8 state:D stack:19256 pid:2887 tgid:2887 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) 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_background_flush fs/fs-writeback.c:2164 [inline] wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0xc33/0xfb0 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 4 locks held by kworker/u4:3/49: #0: ffff888018ac9d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888018ac9d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90000b9fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90000b9fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff8880235660e0 (&type->s_umount_key#54){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff888078f192a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff888078f192a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 4 locks held by kworker/u4:8/2887: #0: ffff888018ac9d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888018ac9d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000a13fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000a13fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff88803d0f40e0 (&type->s_umount_key#54){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff88802169d2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff88802169d2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 2 locks held by getty/4809: #0: ffff88802a8130a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 8 locks held by syz-executor.0/5656: 6 locks held by syz-executor.4/5660: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3477 Comm: kworker/u4:9 Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:209 [inline] RIP: 0010:unwind_next_frame+0x215/0x29e0 arch/x86/kernel/unwind_orc.c:494 Code: 00 00 a0 8b e8 1c 21 53 00 48 39 dd 48 89 6c 24 38 0f 82 27 01 00 00 4c 39 f5 0f 83 1e 01 00 00 48 c7 c0 00 00 00 81 48 29 c5 <48> c1 ed 08 48 c7 c0 fc c8 a6 90 48 c7 c1 00 49 d1 90 48 29 c1 48 RSP: 0018:ffffc900001f07e8 EFLAGS: 00000206 RAX: ffffffff81000000 RBX: ffffffff81000000 RCX: ffff88802c70d940 RDX: ffffc900001f08f5 RSI: ffffffff8ba00000 RDI: ffffffff81603672 RBP: 0000000000603672 R08: ffffffff81404f44 R09: ffffc900001f09b0 R10: 0000000000000003 R11: ffffffff818044c0 R12: ffffc900001f08c0 R13: ffffc900001f0910 R14: ffffffff8ba00000 R15: ffffffff81603673 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055acd5f31680 CR3: 000000000df32000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x150/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x117/0x1d0 kernel/stacktrace.c:122 save_stack+0xfa/0x1f0 mm/page_owner.c:129 __reset_page_owner+0x44/0x2d0 mm/page_owner.c:150 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x95d/0xa80 mm/page_alloc.c:2346 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 rcu_do_batch kernel/rcu/tree.c:2190 [inline] rcu_core+0xd76/0x1810 kernel/rcu/tree.c:2465 __do_softirq+0x2bb/0x942 kernel/softirq.c:553 do_softirq+0x11b/0x1e0 kernel/softirq.c:454 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:381 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x30f/0x3b0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720 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