INFO: task syz.2.14002:12246 blocked for more than 146 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.14002 state:D stack:26080 pid:12246 tgid:12243 ppid:7189 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 __schedule_loop kernel/sched/core.c:7283 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7579 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1666 __rt_mutex_slowlock kernel/locking/rtmutex.c:1743 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1783 [inline] rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1823 __rt_mutex_lock kernel/locking/rtmutex.c:1838 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 epoll_mutex_lock fs/eventpoll.c:2512 [inline] ep_ctl_lock fs/eventpoll.c:2559 [inline] do_epoll_ctl_file+0x9d1/0xed0 fs/eventpoll.c:2636 do_epoll_ctl fs/eventpoll.c:2698 [inline] __do_sys_epoll_ctl fs/eventpoll.c:2715 [inline] __se_sys_epoll_ctl+0x14e/0x210 fs/eventpoll.c:2706 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5193cace59 RSP: 002b:00007f5191ec4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9 RAX: ffffffffffffffda RBX: 00007f5193f26180 RCX: 00007f5193cace59 RDX: 0000000000000008 RSI: 0000000000000001 RDI: 000000000000000b RBP: 00007f5193d42d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5193f26218 R14: 00007f5193f26180 R15: 00007ffd5336a8b8 Showing all locks held in the system: 2 locks held by ktimers/1/30: #0: ffffffff8e0613c0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 1 lock held by khungtaskd/39: #0: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 2 locks held by getty/5369: #0: ffff888035a2c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 5 locks held by kworker/u9:2/5615: #0: ffff888068565138 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90004447c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffff88803a390f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 #3: ffff88803a3900b0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5781 #4: ffffffff8f72fe18 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff8f72fe18 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x340 net/bluetooth/hci_conn.c:1411 3 locks held by kworker/1:0/23173: #0: ffff88813fe16538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc9000d5c7c40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xab/0x10d0 net/wireless/reg.c:2469 2 locks held by syz.1.9141/30605: #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2559 [inline] #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: do_epoll_ctl_file+0x9d1/0xed0 fs/eventpoll.c:2636 #1: ffff88804f128858 (&ep->mtx){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #1: ffff88804f128858 (&ep->mtx){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2573 [inline] #1: ffff88804f128858 (&ep->mtx){+.+.}-{4:4}, at: do_epoll_ctl_file+0xc69/0xed0 fs/eventpoll.c:2636 5 locks held by kworker/u9:1/5727: #0: ffff88803c6c8138 ((wq_completion)hci7){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc900045b7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffff8880251bcf80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 #3: ffff8880251bc0b0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5781 #4: ffffffff8f72fe18 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff8f72fe18 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x340 net/bluetooth/hci_conn.c:1411 3 locks held by kworker/0:2/8872: #0: ffff88813fe17938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90004217c40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x460 net/core/dev_addr_lists.c:1312 6 locks held by kworker/u9:0/11434: #0: ffff88805f2cf938 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90003ec7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffff88804f3c0f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 #3: ffff88804f3c00b0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5781 #4: ffffffff8f72fe18 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff8f72fe18 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x340 net/bluetooth/hci_conn.c:1411 #5: ffff88805b582370 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x92/0x570 net/bluetooth/l2cap_core.c:1779 3 locks held by kworker/u8:37/11695: #0: ffff888031759138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc9000d66fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4221 3 locks held by kworker/u8:40/11698: #0: ffff88813fe54138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc9000d6a7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by syz.8.13999/12237: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3505 1 lock held by syz.2.14002/12246: #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2559 [inline] #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: do_epoll_ctl_file+0x9d1/0xed0 fs/eventpoll.c:2636 1 lock held by syz.5.14003/12252: #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2559 [inline] #0: ffffffff8e3589b8 (epnested_mutex){+.+.}-{4:4}, at: do_epoll_ctl_file+0x9d1/0xed0 fs/eventpoll.c:2636 1 lock held by syz-executor/12278: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4150 7 locks held by syz-executor/12286: #0: ffff8880350d6480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff8880350d6480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff888031bf8c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888029426b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888029426b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ee21ab8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803821f160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff88803821f160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88803821f160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1369 #5: ffff88803974e310 (&devlink->lock_key#5){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799 #6: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x16b/0x7f0 drivers/net/netdevsim/netdev.c:1188 4 locks held by syz-executor/12296: #0: ffff8880350d6480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff8880350d6480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff8880560f4078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888029426b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888029426b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ee21ab8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 1 lock held by syz.6.14028/12371: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: packet_mc_add+0x28/0xb90 net/packet/af_packet.c:3690 1 lock held by syz.6.14028/12372: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: packet_mc_add+0x28/0xb90 net/packet/af_packet.c:3690 3 locks held by syz.6.14028/12373: #0: ffff888036c60928 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2410 #1: ffff88803724b248 (&net->packet.sklist_lock){+.+.}-{4:4}, at: packet_diag_dump+0x1a8/0x1be0 net/packet/diag.c:200 #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: pdiag_put_mclist net/packet/diag.c:47 [inline] #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: sk_diag_fill net/packet/diag.c:160 [inline] #2: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: packet_diag_dump+0x9c5/0x1be0 net/packet/diag.c:207 1 lock held by syz-executor/12378: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/12393: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/12397: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/12405: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/12407: #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac9f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP 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:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30605 Comm: syz.1.9141 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:246 [inline] RIP: 0010:__lock_acquire+0xa56/0x2d10 kernel/locking/lockdep.c:5236 Code: ff 3d 88 8d 67 48 0f b9 3a 90 31 c0 48 83 78 40 00 0f 84 7f 1d 00 00 41 8b 45 20 25 ff 1f 00 00 48 0f a3 05 1c d5 00 12 73 10 <48> 69 c0 c8 00 00 00 48 8d 80 d0 e4 42 93 eb 32 83 3d 23 65 04 18 RSP: 0018:ffffc90005037938 EFLAGS: 00000003 RAX: 000000000000000b RBX: 000000004763c017 RCX: 00000000eeaca948 RDX: 0000000054772d39 RSI: 0000000092305b1c RDI: ffff88802e540000 RBP: 4d8e154400000000 R08: ffffffff825693cb R09: ffffffff8e1cac60 R10: ffffc90005037d70 R11: fffff52000a06fb1 R12: ffff88802e540c50 R13: ffff88802e540c50 R14: ffff88802e540000 R15: 0000000000000002 FS: 00007efdd56de6c0(0000) GS:ffff888125c7e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4ee5381509 CR3: 00000000342a4000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] reverse_path_check fs/eventpoll.c:1691 [inline] ep_insert+0xbd8/0x1820 fs/eventpoll.c:1881 do_epoll_ctl_file+0x8bb/0xed0 fs/eventpoll.c:2651 do_epoll_ctl fs/eventpoll.c:2698 [inline] __do_sys_epoll_ctl fs/eventpoll.c:2715 [inline] __se_sys_epoll_ctl+0x14e/0x210 fs/eventpoll.c:2706 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efdd748ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efdd56de028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9 RAX: ffffffffffffffda RBX: 00007efdd7705fa0 RCX: 00007efdd748ce59 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000009 RBP: 00007efdd7522d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000140 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efdd7706038 R14: 00007efdd7705fa0 R15: 00007fff8104b658