INFO: task syz.5.486:9758 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.486 state:D stack:25592 pid:9758 tgid:9757 ppid:9107 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1819 __rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:245 __super_lock fs/super.c:58 [inline] super_lock+0x289/0x3d0 fs/super.c:122 user_get_super+0xc8/0x120 fs/super.c:1001 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x540/0x9e0 fs/quota/quota.c:917 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: 0033:0x7f7623cfce59 RSP: 002b:00007f7621f4e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f7623f75fa0 RCX: 00007f7623cfce59 RDX: 0000000000000000 RSI: 00002000000002c0 RDI: ffffffff80000201 RBP: 00007f7623d92d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7623f76038 R14: 00007f7623f75fa0 R15: 00007ffcd68788e8 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/41: #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90000b27c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90000b27c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f348920 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120 net/wireless/core.c:1810 3 locks held by kworker/u8:11/3131: #0: ffff888032436138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888032436138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000dfb7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000dfb7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 2 locks held by getty/5349: #0: ffff888036c2d0a0 (&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+0x462/0x13a0 drivers/tty/n_tty.c:2211 6 locks held by syz-executor/5874: 1 lock held by syz.5.486/9758: #0: ffff88803e8c40d0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803e8c40d0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x289/0x3d0 fs/super.c:122 3 locks held by syz-executor/10733: #0: ffffffff8f3c76e0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f3c74f8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f3c74f8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f3c74f8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_register_hw+0x388d/0x4a70 net/mac80211/main.c:1558 1 lock held by syz-executor/10751: #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5039 1 lock held by syz-executor/10794: #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5039 7 locks held by syz-executor/11035: #0: ffff88802a47e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #0: ffff88802a47e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff888045e5fc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880292405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880292405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ebcfa58 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803fe02160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88803fe02160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff88803fe02160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372 #5: ffff8880542fe310 (&devlink->lock_key#31){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799 #6: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x16b/0x7f0 drivers/net/netdevsim/netdev.c:1188 4 locks held by syz-executor/11090: #0: ffff88802a47e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #0: ffff88802a47e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff888034702878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880292405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880292405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ebcfa58 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 2 locks held by sed/11278: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 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 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 04/18/2026 RIP: 0010:chain_hlock_class_idx kernel/locking/lockdep.c:438 [inline] RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:6198 [inline] RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:6236 [inline] RIP: 0010:zap_class+0xf1/0x340 kernel/locking/lockdep.c:6281 Code: 08 c1 75 d7 45 8b 75 00 41 f6 c6 fc 0f 84 e1 00 00 00 41 c1 ee 08 4a 8d 1c 75 30 73 73 92 49 81 fe 00 00 50 00 73 2f 0f b7 03 <25> ff 1f 00 00 49 39 c7 74 33 49 ff c6 41 8b 45 00 89 c1 c1 e9 08 RSP: 0018:ffffc90000087c50 EFLAGS: 00000087 RAX: 0000000000000774 RBX: ffffffff9277c2ea RCX: 0000000000073700 RDX: ffffffff932e7358 RSI: 0000000000000004 RDI: 00000000001bcd8c RBP: ffffffff937277d0 R08: ffffffff81add4b8 R09: ffffffff8dfc8180 R10: dffffc0000000000 R11: fffffbfff1f11e7f R12: 0000000000072d72 R13: ffffffff9380e0d0 R14: 00000000000227dd R15: 0000000000000ec8 FS: 0000000000000000(0000) GS:ffff888126274000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd677a3a6b0 CR3: 000000000ddb6000 CR4: 00000000003526f0 Call Trace: __lockdep_free_key_range kernel/locking/lockdep.c:6407 [inline] lockdep_unregister_key+0x1c3/0x350 kernel/locking/lockdep.c:6609 wq_unregister_lockdep kernel/workqueue.c:4941 [inline] pwq_release_workfn+0x6ce/0x8c0 kernel/workqueue.c:5237 kthread_worker_fn+0x4ee/0xb20 kernel/kthread.c:1025 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