INFO: task syz.3.345:7898 blocked for more than 142 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.345 state:D stack:24664 pid:7898 tgid:7898 ppid:5837 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 ima_check_last_writer security/integrity/ima/ima_main.c:192 [inline] ima_file_free+0x16c/0x460 security/integrity/ima/ima_main.c:233 security_file_release+0x93/0x150 security/security.c:2398 __fput+0x3b3/0xa70 fs/file_table.c:462 task_work_run+0x1d4/0x260 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:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa7c918f749 RSP: 002b:00007ffca15788e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fa7c93e7da0 RCX: 00007fa7c918f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fa7c93e7da0 R08: 000000000000010c R09: 0000000fa1578bdf R10: 00007fa7c93e7cb0 R11: 0000000000000246 R12: 000000000003ee5e R13: 00007ffca15789e0 R14: ffffffffffffffff R15: 00007ffca1578a00 Showing all locks held in the system: 1 lock held by ksoftirqd/1/23: 1 lock held by khungtaskd/31: #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:6/728: #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc900036e7b80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/1:2/932: #0: ffff88801dedf548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90003c87b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff888028e32198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888028e32198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff888058585198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888058585198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 2 locks held by kworker/u8:11/3453: 2 locks held by klogd/5187: #0: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 #1: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 2 locks held by dhcpcd/5493: #0: ffff888079d846f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2267 #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5583: #0: ffff888034ddd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 4 locks held by udevd/6240: #0: ffff88807a391668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:183 #1: ffff88802f1ee088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff8880680a8c38 (kn->active#31){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880680a8c38 (kn->active#31){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff888058585198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff888058585198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by kworker/1:11/7292: #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000e787b80 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 1 lock held by syz.3.345/7898: #0: ffff888056e8ce38 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_check_last_writer security/integrity/ima/ima_main.c:192 [inline] #0: ffff888056e8ce38 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_file_free+0x16c/0x460 security/integrity/ima/ima_main.c:233 1 lock held by syz.3.345/7903: 3 locks held by kworker/u8:26/9040: #0: ffff88814d239948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000baafb80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 5 locks held by kworker/u8:28/9230: #0: ffff88801baa7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90004a77b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f504e10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670 #3: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x9e0 net/core/dev.c:13041 #4: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #4: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956 2 locks held by syz-executor/9464: #0: ffffffff8fa43748 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8fa43748 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8fa43748 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by syz-executor/9481: #0: ffffffff8f504e10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x200 drivers/net/wireguard/device.c:419 4 locks held by syz.5.598/9544: #0: ffff88805c0f0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88805c0f0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715 #1: ffff88805c0f00c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5329 #2: ffffffff8f683f08 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8f683f08 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2643 #3: ffff88807b85eb38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __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:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9230 Comm: kworker/u8:28 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net RIP: 0010:__lock_acquire+0x6c7/0x2cf0 kernel/locking/lockdep.c:5207 Code: bc 00 00 00 4c 8b 74 24 08 4c 89 f7 4c 89 ee ba 08 00 00 00 e8 9a 47 00 00 31 ed 85 c0 0f 84 6d 0d 00 00 83 3d 09 8c 0c 18 00 <75> 13 48 63 44 24 18 48 0f a3 05 1a fc 08 12 0f 83 8a 1e 00 00 49 RSP: 0018:ffffc90000a08638 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff888027aa5b80 RCX: ffffffff9348b550 RDX: 0000000000000008 RSI: ffff888027aa67f0 RDI: ffff888027aa5b80 RBP: 0000000000000000 R08: ffffffff81af64e5 R09: ffffffff99af4508 R10: 000000000000000b R11: 0000000000000100 R12: 0000000000000054 R13: ffff888027aa67f0 R14: ffff888027aa5b80 R15: ffff888027aa66b0 FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f263deb2e9c CR3: 0000000055d54000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0xcf/0x1c0 include/linux/seqlock.h:72 ktime_get+0x45/0x200 kernel/time/timekeeping.c:824 __hrtimer_start_range_ns kernel/time/hrtimer.c:1249 [inline] hrtimer_start_range_ns+0x339/0x1080 kernel/time/hrtimer.c:1322 hrtimer_start include/linux/hrtimer.h:259 [inline] dummy_timer+0x43da/0x45b0 drivers/usb/gadget/udc/dummy_hcd.c:2008 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 44 41 01 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90004a76e38 EFLAGS: 00000206 RAX: 9219846f4ef69100 RBX: 0000000000000000 RCX: 9219846f4ef69100 RDX: 00000000ebc1f585 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960 RBP: ffffffff81742f85 R08: ffffffff81742f85 R09: ffffffff8e13f2e0 R10: ffffc90004a76ff8 R11: ffffffff81ad9d50 R12: 0000000000000002 R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239 kernfs_put+0x18e/0x470 fs/kernfs/dir.c:591 kernfs_remove_by_name_ns+0xb7/0x130 fs/kernfs/dir.c:1721 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2f0 fs/sysfs/group.c:328 netdev_queue_update_kobjects+0x5a6/0x6d0 net/core/net-sysfs.c:2070 remove_queue_kobjects net/core/net-sysfs.c:2170 [inline] netdev_unregister_kobject+0x11f/0x450 net/core/net-sysfs.c:2325 unregister_netdevice_many_notify+0x1ddd/0x2340 net/core/dev.c:12435 unregister_netdevice_many net/core/dev.c:12463 [inline] default_device_exit_batch+0x964/0x9e0 net/core/dev.c:13055 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x525/0x990 net/core/net_namespace.c:252 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246