INFO: task syz-executor:4191 blocked for more than 143 seconds. Not tainted 5.15.189-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21216 pid: 4191 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 gfs2_gl_hash_clear+0x1a4/0x2f0 fs/gfs2/glock.c:2183 gfs2_put_super+0x769/0x7d0 fs/gfs2/super.c:624 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f8c1dfc8cd7 RSP: 002b:00007fff6e357d98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f8c1e049b55 RCX: 00007f8c1dfc8cd7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff6e357e50 RBP: 00007fff6e357e50 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff6e358ee0 R13: 00007f8c1e049b55 R14: 0000000000058444 R15: 00007fff6e358f20 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by dhcpcd/3854: #0: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647 2 locks held by getty/3949: #0: ffff88814ce5a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4191: #0: ffff88807b8980e0 (&type->s_umount_key#74){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 3 locks held by kworker/u4:11/4387: 5 locks held by kworker/u4:19/5589: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000361fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22a2d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589 #3: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:11620 [inline] #3: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x149/0x390 net/core/dev.c:11658 #4: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #4: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 3 locks held by kworker/0:10/5627: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000310fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 3 locks held by kworker/u4:22/5868: #0: ffff888016879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000356fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 2 locks held by kworker/u4:23/6477: 3 locks held by kworker/1:12/7747: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003cafd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 2 locks held by kworker/1:14/7750: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003cefd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/1:18/7995: #0: ffff888141781538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000378fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888023e2f220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #2: ffff888023e2f220 (&dev->mutex){....}-{3:3}, at: hub_event+0x18f/0x4fa0 drivers/usb/core/hub.c:5781 1 lock held by syz-executor/8228: #0: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647 1 lock held by syz.5.715/8289: #0: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5589 Comm: kworker/u4:19 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d c0 ac f1 0b 48 89 de 5b e9 77 99 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 94 ab 8a 7e 65 8b 15 95 ab 8a 7e 81 e2 00 RSP: 0018:ffffc9000361f468 EFLAGS: 00000202 RAX: ffffffff87d918d2 RBX: 0000000000000001 RCX: ffff88802171bb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520006c3e94 R11: 1ffff920006c3e94 R12: ffff888148650600 R13: 0000000000000000 R14: 00000000000002e2 R15: ffff888078ec2000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff342ed3178 CR3: 000000001fe80000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: neigh_flush_dev+0x1bf/0x990 net/core/neighbour.c:338 __neigh_ifdown+0x39/0x3a0 net/core/neighbour.c:391 neigh_ifdown+0x1b/0x30 net/core/neighbour.c:408 rt6_disable_ip+0x602/0x690 net/ipv6/route.c:4922 addrconf_ifdown+0x149/0x1970 net/ipv6/addrconf.c:3776 addrconf_notify+0x445/0xf00 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] unregister_netdevice_many+0xf57/0x18f0 net/core/dev.c:11134 default_device_exit_batch+0x336/0x390 net/core/dev.c:11667 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287