INFO: task kworker/1:5:10561 blocked for more than 143 seconds. Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:24272 pid:10561 tgid:10561 ppid:2 task_flags:0x4288060 flags:0x00004000 Workqueue: md_misc mddev_delayed_delete Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0xb1/0x2b0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x32f/0x600 kernel/sched/completion.c:148 devtmpfs_submit_req drivers/base/devtmpfs.c:122 [inline] devtmpfs_delete_node+0x217/0x300 drivers/base/devtmpfs.c:171 device_del+0x334/0x9b0 drivers/base/core.c:3834 del_gendisk+0x798/0xad0 block/genhd.c:734 md_kobj_release+0xaf/0xd0 drivers/md/md.c:5749 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x231/0x480 lib/kobject.c:737 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac5/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 2 locks held by kdevtmpfs/26: #0: ffff88801c2d8950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #0: ffff88801c2d8950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __kern_path_locked+0x1ca/0x430 fs/namei.c:2765 #1: ffffffff8f48cb48 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev block/genhd.c:820 [inline] #1: ffffffff8f48cb48 (major_names_lock){+.+.}-{4:4}, at: blk_request_module+0x38/0x2a0 block/genhd.c:836 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 2 locks held by dhcpcd/5500: #0: ffff88807eb596d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2388 #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6823 2 locks held by getty/5586: #0: ffff888031ab60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033362f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 6 locks held by kworker/u8:10/5994: 4 locks held by kworker/u8:14/6154: #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000b467c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b467c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900f0a90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608 #3: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xde/0x880 net/core/dev.c:12524 3 locks held by kworker/u8:16/9632: #0: ffff8880312a1948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880312a1948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000fe4fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000fe4fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x110/0x16a0 net/ipv6/addrconf.c:4195 2 locks held by kworker/1:5/10561: #0: ffff8881446f0148 ((wq_completion)md_misc){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8881446f0148 ((wq_completion)md_misc){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000de17c60 ((work_completion)(&mddev->del_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000de17c60 ((work_completion)(&mddev->del_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 3 locks held by kworker/u8:2/14162: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc900038f7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900038f7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by kworker/1:8/15649: #0: ffff8881446d7548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8881446d7548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90004137c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004137c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff888144b34198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff888144b34198 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5859 1 lock held by syz-executor/17549: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3390 1 lock held by syz-executor/17781: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x831/0x11b0 net/ipv6/addrconf.c:5028 2 locks held by syz-executor/17929: #0: ffffffff8f865e20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f865e20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f865e20 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:570 #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd68/0x1fe0 net/core/rtnetlink.c:4064 2 locks held by syz.1.3260/18249: #0: ffff88805d3456d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2388 #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6823 1 lock held by syz.8.3263/18256: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3390 1 lock held by syz-executor/18258: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz.6.3275/18329: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xd70 net/core/rtnetlink.c:6961 1 lock held by syz-executor/18334: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18339: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18342: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18346: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18350: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18354: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18358: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18362: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18366: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18371: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18375: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18380: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18385: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 1 lock held by syz-executor/18388: #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x406/0x1c40 net/ipv4/devinet.c:979 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 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: 0 Comm: swapper/1 Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: 7e af e0 f4 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 53 7e 18 00 f3 0f 1e fa fb f4 53 af e0 f4 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197dc0 EFLAGS: 00000286 RAX: 0d6aaefb1e6e7100 RBX: ffffffff8197272e RCX: ffffffff8c2fb89c RDX: 0000000000000001 RSI: ffffffff8e6497f7 RDI: ffffffff8ca1b680 RBP: ffffc90000197f20 R08: ffff8880b8732b5b R09: 1ffff110170e656b R10: dffffc0000000000 R11: ffffed10170e656c R12: 1ffff92000032fd2 R13: 1ffff11003adcb40 R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88812509a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc6f0dad28 CR3: 000000000eb38000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x22e/0x5d0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 start_secondary+0xfe/0x100 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147