INFO: task kworker/u8:12:1184 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/u8:12 state:D stack:21504 pid:1184 tgid:1184 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 io_schedule+0x80/0xe0 kernel/sched/core.c:8109 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:5589 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:22576 pid:5589 tgid:5589 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 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: 0033:0x7f27d6fae017 RSP: 002b:00007ffe914bfd48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f27d7042120 RCX: 00007f27d6fae017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe914bfe00 RBP: 00007ffe914bfe00 R08: 00007ffe914c0e00 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe914c0e90 R13: 00007f27d7042120 R14: 0000000000080b3d R15: 00007ffe914c0ed0 Showing all locks held in the system: 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 6 locks held by kworker/u8:4/66: #0: ffff8880326fe138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff8880326fe138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000151fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000151fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356078 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f356078 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 #3: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x215/0x1670 net/ipv6/ndisc.c:482 #4: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:234 #5: ffff88801a00ac58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff88801a00ac58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3736 [inline] #5: ffff88801a00ac58 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7103 4 locks held by kworker/u8:9/1131: #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006177c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006177c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f347340 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffff88803fba1878 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 2 locks held by kworker/u8:12/1184: #0: ffff88801f2bf138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801f2bf138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006277c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006277c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 1 lock held by klogd/4950: #0: ffff88801a00ac58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffff88801a00ac58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3736 [inline] #0: ffff88801a00ac58 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7103 2 locks held by getty/5347: #0: ffff8880366dd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5589: #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 3 locks held by kworker/1:1/10320: #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc900050dfc40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc900050dfc40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356078 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x450 net/core/dev_addr_lists.c:1312 5 locks held by kworker/u8:0/10423: 3 locks held by kworker/u9:0/10532: #0: ffff88805f1c4938 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88805f1c4938 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc900056cfc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc900056cfc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff8880572f0f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 1 lock held by syz.7.486/10671: #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 5 locks held by kworker/u8:17/11047: 1 lock held by syz.0.493/11135: #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880299c80d0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/11329: 7 locks held by syz-executor/11634: 3 locks held by syz.2.586/12012: 5 locks held by syz.2.586/12013: 4 locks held by syz.2.586/12049: 4 locks held by syz.9.587/12017: 1 lock held by udevadm/12037: 1 lock held by syz.5.589/12046: 2 locks held by cmp/12048: ============================================= 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: 12012 Comm: syz.2.586 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x197b/0x2cf0 kernel/locking/lockdep.c:5237 Code: 13 25 ff 0f 00 00 39 05 df 9c d1 11 73 06 89 05 d7 9c d1 11 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 50 54 e9 RSP: 0018:ffffc9000589ee20 EFLAGS: 00000006 RAX: ffffffff960644b8 RBX: 0000000000000145 RCX: 0000000000000006 RDX: ffffffff95f5a0c8 RSI: ffff888038c86900 RDI: 0000000000000145 RBP: 9c0859f765e1510e R08: ffffc9000589ede8 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff81a0ac00 R12: ffffffff95f6c2d8 R13: ffffffff931340b8 R14: ffff888038c85c40 R15: 0000000000000005 FS: 00007f1d16d7e6c0(0000) GS:ffff88812617c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f888d626000 CR3: 000000008b7d6000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 debug_object_activate+0x72/0x520 lib/debugobjects.c:835 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] remove_and_enqueue_same_base kernel/time/hrtimer.c:1259 [inline] __hrtimer_start_range_ns kernel/time/hrtimer.c:1396 [inline] hrtimer_start_range_ns+0x57c/0xef0 kernel/time/hrtimer.c:1491 hrtimer_start include/linux/hrtimer.h:220 [inline] hrtick_cond_restart kernel/sched/core.c:924 [inline] hrtick_schedule_exit kernel/sched/core.c:986 [inline] finish_lock_switch kernel/sched/core.c:5123 [inline] finish_task_switch+0x3cd/0xbe0 kernel/sched/core.c:5242 context_switch kernel/sched/core.c:5390 [inline] __schedule+0x1689/0x54c0 kernel/sched/core.c:7188 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:make_vfsuid+0x4/0xa0 fs/mnt_idmapping.c:83 Code: ff e8 a0 46 e0 ff e9 51 ff ff ff cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 41 56 53 89 d3 49 89 f7 49 89 fe e8 9a 3d 79 ff 49 81 fe 40 RSP: 0018:ffffc9000589f4e8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880628e9268 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8de631c0 RDI: ffffffff8e145c40 RBP: ffff888062953800 R08: ffffffff8b1e5760 R09: ffffffff8dfc8140 R10: dffffc0000000000 R11: fffffbfff1f11a5f R12: dffffc0000000000 R13: ffff888062953810 R14: ffff8880629537e8 R15: 1ffff1100c52a702 i_uid_into_vfsuid include/linux/fs.h:1450 [inline] ovl_copyattr+0x286/0x670 fs/overlayfs/util.c:1507 ovl_inode_init+0x130/0x640 fs/overlayfs/inode.c:886 ovl_get_root+0x642/0x800 fs/overlayfs/super.c:1349 ovl_fill_super_creds fs/overlayfs/super.c:1530 [inline] ovl_fill_super+0x430c/0x5e20 fs/overlayfs/super.c:1560 vfs_get_super fs/super.c:1327 [inline] get_tree_nodev+0xbb/0x150 fs/super.c:1346 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d18b2cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1d16d7e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f1d18da5fa0 RCX: 00007f1d18b2cdd9 RDX: 0000200000000180 RSI: 0000200000000140 RDI: 0000000000000000 RBP: 00007f1d18bc2d69 R08: 00002000000001c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1d18da6038 R14: 00007f1d18da5fa0 R15: 00007ffc4ce1f068