INFO: task kworker/u8:9:1035 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/u8:9 state:D stack:20872 pid:1035 tgid:1035 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:1) Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 io_schedule+0x80/0xe0 kernel/sched/core.c:8154 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x281/0xbe0 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:1607 [inline] __writeback_single_inode+0x6af/0xf90 fs/fs-writeback.c:1850 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079 wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2264 wb_do_writeback fs/fs-writeback.c:2432 [inline] wb_workfn+0x437/0x10f0 fs/fs-writeback.c:2477 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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:5597 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:21736 pid:5597 tgid:5597 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 wb_wait_for_completion+0x3b2/0x700 fs/fs-writeback.c:227 __writeback_inodes_sb_nr+0x246/0x2e0 fs/fs-writeback.c:2933 sync_filesystem+0xa2/0x250 fs/sync.c:54 generic_shutdown_super+0x77/0x2d0 fs/super.c:626 kill_block_super+0x44/0x90 fs/super.c:1665 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 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:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __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:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f131d2af0d7 RSP: 002b:00007ffca8b6a338 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f131d34330a RCX: 00007f131d2af0d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffca8b6a3f0 RBP: 00007ffca8b6a3f0 R08: 00007ffca8b6b3f0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffca8b6b480 R13: 00007f131d34330a R14: 000000000008e3db R15: 00007ffca8b6b4c0 Showing all locks held in the system: 8 locks held by kworker/u8:0/12: 6 locks held by kworker/u8:1/13: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5a2e80 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff888034f04160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff888034f04160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888034f04160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff8880372be310 (&devlink->lock_key#24){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff8880372be310 (&devlink->lock_key#24){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff8880372be310 (&devlink->lock_key#24){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 #5: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1058 [inline] #5: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x87f/0x1160 drivers/net/netdevsim/netdev.c:1152 1 lock held by khungtaskd/37: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/39: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000b07c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000b07c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by kworker/u8:9/1035: #0: ffff88801f2d7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801f2d7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004f2fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004f2fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 3 locks held by kworker/u8:10/1422: 3 locks held by kworker/u8:14/1941: #0: ffff888032796938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888032796938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900060f7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc900060f7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4229 1 lock held by dhcpcd/5260: 2 locks held by getty/5352: #0: ffff88803628e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5597: #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509 3 locks held by kworker/1:3/9750: #0: ffff88813ff1b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff1b938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000395fc40 (netdev_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000395fc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x72/0x7f0 net/core/netdev_work.c:116 3 locks held by kworker/0:0/9751: 1 lock held by syz.7.797/11668: #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.7.797/11672: #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.8.810/11791: #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.8.810/11792: #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888021ad60d0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by syz-executor/11822: #0: ffffffff8f622ce0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f622af8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f622af8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f622af8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device_doit+0x170/0x2120 drivers/net/wireguard/netlink.c:484 4 locks held by syz-executor/11851: #0: ffff8880351de500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff8880351de500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888033a0dc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff88802951ab48 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802951ab48 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee26cd8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 10 locks held by syz-executor/11902: 2 locks held by syz-executor/12116: #0: ffffffff8ed16868 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ed16868 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ed16868 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5b1a38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 3 locks held by syz.4.836/12214: 1 lock held by dhcpcd-run-hook/12216: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 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: 12214 Comm: syz.4.836 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:page_table_check_set+0x2ba/0x530 mm/page_table_check.c:121 Code: 89 ee e8 79 74 8f ff 45 85 ed 0f 85 61 02 00 00 48 8d 7b 04 be 04 00 00 00 e8 12 e3 f8 ff 41 bd 01 00 00 00 f0 44 0f c1 6b 04 <41> 8d 75 01 31 ff e8 4b 74 8f ff 41 ff c5 0f 88 2b 02 00 00 e8 8d RSP: 0000:ffffc90003d6fb90 EFLAGS: 00000202 RAX: ffffffff82365801 RBX: ffff88801a915ed8 RCX: ffffffff823658de RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801a915edc RBP: 0000000000000001 R08: ffff88801a915edf R09: 1ffff11003522bdb R10: dffffc0000000000 R11: ffffed1003522bdc R12: 000000000000b795 R13: 0000000000000072 R14: 0000000000000001 R15: ffff88801a915e90 FS: 00007fe6ed3d66c0(0000) GS:ffff888125c42000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe6e504b000 CR3: 0000000070c38000 CR4: 00000000003526f0 Call Trace: page_table_check_ptes_set include/linux/page_table_check.h:83 [inline] set_ptes include/linux/pgtable.h:447 [inline] do_anonymous_page mm/memory.c:5330 [inline] do_pte_missing+0x28b0/0x28f0 mm/memory.c:4564 handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault mm/memory.c:6517 [inline] handle_mm_fault+0xd28/0x13f0 mm/memory.c:6686 do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fe6ef0351ce Code: c1 49 39 4f 08 72 54 8d 4d ff 85 ed 74 3b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 47 10 48 83 c0 01 RSP: 002b:00007fe6ed3d5470 EFLAGS: 00010206 RAX: 0000000000095001 RBX: 00007fe6ed3d5530 RCX: 0000000000000050 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007fe6ed3d55d0 RBP: 0000000000000102 R08: 00007fe6e4fb6000 R09: 0000000000095000 R10: 0000000000000000 R11: 00007fe6ed3d5540 R12: 0000000000000001 R13: 00007fe6ef233e00 R14: 0000000000000000 R15: 00007fe6ed3d55d0