INFO: task kworker/u8:10:1426 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:10 state:D stack:20520 pid:1426 tgid:1426 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:1) Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 io_schedule+0x81/0xe0 kernel/sched/core.c:7871 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x26e/0xb10 fs/jfs/jfs_txnmgr.c:375 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:1564 [inline] __writeback_single_inode+0x6f4/0x1000 fs/fs-writeback.c:1784 writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:2015 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195 wb_do_writeback fs/fs-writeback.c:2342 [inline] wb_workfn+0x40e/0xf00 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.1.152:8456 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.152 state:D stack:22216 pid:8456 tgid:8454 ppid:7887 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 __writeback_inodes_sb_nr+0x1f7/0x270 fs/fs-writeback.c:2787 sync_filesystem+0xa2/0x250 fs/sync.c:54 jfs_reconfigure+0xc6/0xa00 fs/jfs/super.c:370 reconfigure_super+0x227/0x890 fs/super.c:1076 do_remount fs/namespace.c:3279 [inline] path_mount+0xd1a/0xfe0 fs/namespace.c:4029 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd2ae97076a RSP: 002b:00007fd2acbcde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fd2acbcdef0 RCX: 00007fd2ae97076a RDX: 0000200000000180 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 0000200000000180 R08: 00007fd2acbcdef0 R09: 0000000002046022 R10: 0000000002046022 R11: 0000000000000246 R12: 0000200000000000 R13: 00007fd2acbcdeb0 R14: 0000000000000000 R15: 00002000000002c0 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000117ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000117ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by khungtaskd/38: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:8/1301: #0: ffff88814d4fe138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814d4fe138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900050c7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900050c7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 2 locks held by kworker/u8:10/1426: #0: ffff8881404ca938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881404ca938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900055d7ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900055d7ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 2 locks held by dhcpcd/5465: #0: ffffffff8ea5c8d8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1337 #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:577 2 locks held by getty/5557: #0: ffff88823bf340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 6 locks held by kworker/u8:5/7775: #0: ffff88801a294938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a294938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900053d7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900053d7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea6b560 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffff888029adc0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff888029adc0d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff888029adc0d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506 #4: ffff88802771f300 (&devlink->lock_key#42){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff88802771f300 (&devlink->lock_key#42){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff88802771f300 (&devlink->lock_key#42){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506 #5: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 1 lock held by syz.1.152/8456: #0: ffff888062f640d0 (&type->s_umount_key#84){+.+.}-{4:4}, at: do_remount fs/namespace.c:3276 [inline] #0: ffff888062f640d0 (&type->s_umount_key#84){+.+.}-{4:4}, at: path_mount+0xcd4/0xfe0 fs/namespace.c:4029 1 lock held by udevd/8722: 7 locks held by syz-executor/9099: #0: ffff8880342ca480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline] #0: ffff8880342ca480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805d990878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888145722b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888145722b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e30a298 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff888048e040d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff888048e040d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff888048e040d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff888036b7f300 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721 #6: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xe5/0x670 drivers/net/netdevsim/netdev.c:1173 2 locks held by syz-executor/9564: #0: ffffffff8ef94ca0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ef94ca0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8ef94ca0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/9733: #0: ffffffff8ea6b560 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576 #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3971 2 locks held by syz.6.246/9764: #0: ffff88802387c480 (sb_writers#18){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160 #1: ffff88805e9090a8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff88805e9090a8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: btrfs_inode_lock+0x51/0xe0 fs/btrfs/inode.c:365 5 locks held by syz.6.246/9818: 1 lock held by syz.6.246/9820: #0: ffff88805e9090a8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff88805e9090a8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: process_measurement+0x3de/0x1a40 security/integrity/ima/ima_main.c:280 1 lock held by syz.6.246/9825: #0: ffff88805e9090a8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff88805e9090a8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: process_measurement+0x3de/0x1a40 security/integrity/ima/ima_main.c:280 1 lock held by syz.5.247/9767: 2 locks held by udevadm/9816: 1 lock held by udevadm/9827: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3 Comm: pool_workqueue_ Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:6197 [inline] RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:6236 [inline] RIP: 0010:zap_class+0xc2/0x360 kernel/locking/lockdep.c:6281 Code: 49 81 fc 00 00 08 00 0f 84 a5 01 00 00 4e 8b 2c e5 40 43 89 92 4d 85 ed 0f 94 c0 49 83 c5 f8 0f 94 c1 08 c1 75 d7 45 8b 7d 00 <41> f6 c7 fc 0f 84 e2 00 00 00 41 c1 ef 08 4e 8d 34 7d 10 43 ce 91 RSP: 0018:ffffc90000087ba0 EFLAGS: 00000046 RAX: 0000000000035300 RBX: 0000000000000ae0 RCX: 0000000000035300 RDX: ffffffff92cb4368 RSI: ffffffff92cb4368 RDI: ffffffff9276c220 RBP: ffffffff92cd47b0 R08: 0000000000000000 R09: ffffffff81a96208 R10: dffffc0000000000 R11: fffffbfff1deee4f R12: 000000000001a84c R13: ffffffff932c2430 R14: ffffffff91d4eaa2 R15: 00000000114e5520 FS: 0000000000000000(0000) GS:ffff888126cc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000267000 CR3: 00000000554ec000 CR4: 00000000003526f0 Call Trace: __lockdep_free_key_range kernel/locking/lockdep.c:6407 [inline] lockdep_unregister_key+0x1a6/0x310 kernel/locking/lockdep.c:6609 wq_unregister_lockdep kernel/workqueue.c:4848 [inline] pwq_release_workfn+0x6d2/0x870 kernel/workqueue.c:5144 kthread_worker_fn+0x507/0xb60 kernel/kthread.c:1010 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245