INFO: task kworker/u8:15:1438 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:15 state:D stack:21504 pid:1438 tgid:1438 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 io_schedule+0x80/0xe0 kernel/sched/core.c:8110 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:376 jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1584 [inline] __writeback_single_inode+0x75d/0x10e0 fs/fs-writeback.c:1827 writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056 wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241 wb_do_writeback fs/fs-writeback.c:2388 [inline] wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:5611 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21152 pid:5611 tgid:5611 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227 __writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847 sync_filesystem+0xa2/0x250 fs/sync.c:54 generic_shutdown_super+0x77/0x2d0 fs/super.c:625 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efe7ffde017 RSP: 002b:00007ffc675d78a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007efe80072120 RCX: 00007efe7ffde017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc675d7960 RBP: 00007ffc675d7960 R08: 00007ffc675d8960 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc675d89f0 R13: 00007efe80072120 R14: 000000000003b576 R15: 00007ffc675d8a30 Showing all locks held in the system: 12 locks held by kworker/0:0/9: 5 locks held by kworker/u8:0/12: 4 locks held by rcuc/1/28: 1 lock held by khungtaskd/38: #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:9/1135: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006257c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006257c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 9 locks held by kworker/u8:13/1398: 2 locks held by kworker/u8:15/1438: #0: ffff88801aef4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801aef4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006ae7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006ae7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 2 locks held by getty/5357: #0: ffff88803761d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5611: #0: ffff88806427e0d0 (&type->s_umount_key#113){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806427e0d0 (&type->s_umount_key#113){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88806427e0d0 (&type->s_umount_key#113){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 10 locks held by syz-executor/7131: 1 lock held by syz.0.385/7457: #0: ffff88806427e0d0 (&type->s_umount_key#113){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88806427e0d0 (&type->s_umount_key#113){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.7.587/8600: 2 locks held by syz.1.588/8618: 3 locks held by syz.4.595/8629: 3 locks held by udevadm/8632: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1021 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4879 [inline] RIP: 0010:__lock_acquire+0x524/0x2cf0 kernel/locking/lockdep.c:5187 Code: 00 48 83 c3 28 41 89 c4 49 39 cf 0f 8d c7 00 00 00 49 83 ff 31 0f 83 83 00 00 00 8b 03 25 ff 1f 00 00 48 0f a3 05 4c dd d1 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 30 23 13 93 eb 32 83 3d 53 6d RSP: 0000:ffffc900059ff6f8 EFLAGS: 00000003 RAX: 00000000000009d6 RBX: ffff888026e24998 RCX: 00000000ffffffff RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888026e249f0 R08: ffffffff8ae3926c R09: ffffffff8dfc8140 R10: dffffc0000000000 R11: ffffed1006ba3f17 R12: ffffffffffffff05 R13: ffff888026e249f0 R14: ffff888026e23d80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126179000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0a6c18b008 CR3: 00000000324e6000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:764 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:836 [inline] batadv_iv_ogm_schedule+0x47d/0xf60 net/batman-adv/bat_iv_ogm.c:876 batadv_iv_send_outstanding_bat_ogm_packet+0x6c8/0x7e0 net/batman-adv/bat_iv_ogm.c:1712 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245