INFO: task syz.3.762:11593 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.3.762 state:D stack:26520 pid:11593 tgid:11589 ppid:10962 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: 0033:0x7fbc0170ce59 RSP: 002b:00007fbbff924028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9 RAX: ffffffffffffffda RBX: 00007fbc01986180 RCX: 00007fbc0170ce59 RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000006 RBP: 00007fbc017a2d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbc01986218 R14: 00007fbc01986180 R15: 00007ffdf261b548 Showing all locks held in the system: 2 locks held by ktimers/1/30: #0: ffffffff8de613c0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 1 lock held by khungtaskd/39: #0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 2 locks held by getty/5366: #0: ffff888036b540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003ccb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:22/5829: #0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90005e0fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 6 locks held by kworker/u8:24/5857: #0: ffff88801b69e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc9000608fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffff8880288b6160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff8880288b6160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff8880288b6160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555 #4: ffff888063bda310 (&devlink->lock_key#44){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff888063bda310 (&devlink->lock_key#44){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff888063bda310 (&devlink->lock_key#44){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555 #5: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163 3 locks held by syz.2.380/7176: #0: ffffffff8e1589b8 (epnested_mutex){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #0: ffffffff8e1589b8 (epnested_mutex){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2559 [inline] #0: ffffffff8e1589b8 (epnested_mutex){+.+.}-{4:4}, at: do_epoll_ctl_file+0x9d1/0xed0 fs/eventpoll.c:2636 #1: ffff88801afdd058 (&ep->mtx){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #1: ffff88801afdd058 (&ep->mtx){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2573 [inline] #1: ffff88801afdd058 (&ep->mtx){+.+.}-{4:4}, at: do_epoll_ctl_file+0xc69/0xed0 fs/eventpoll.c:2636 #2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: reverse_path_check fs/eventpoll.c:1691 [inline] #2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: ep_insert+0xbbb/0x1820 fs/eventpoll.c:1881 3 locks held by kworker/u8:4/9489: #0: ffff888032a2c938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293 #1: ffffc90004527c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294 #2: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4761 7 locks held by syz-executor/11540: #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff888060850078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ec05258 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff8880628cc160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff8880628cc160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff8880628cc160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1369 #5: ffff8880403c6310 (&devlink->lock_key#43){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799 #6: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x16b/0x7f0 drivers/net/netdevsim/netdev.c:1188 4 locks held by syz-executor/11559: #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff888063303c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ec05258 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/11574: #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88803ce3e478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ec05258 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 1 lock held by syz.3.762/11593: #0: ffffffff8e1589b8 (epnested_mutex){+.+.}-{4:4}, at: epoll_mutex_lock fs/eventpoll.c:2512 [inline] #0: ffffffff8e1589b8 (epnested_mutex){+.+.}-{4:4}, at: ep_ctl_lock fs/eventpoll.c:2559 [inline] #0: ffffffff8e1589b8 (epnested_mutex){+.+.}-{4:4}, at: do_epoll_ctl_file+0x9d1/0xed0 fs/eventpoll.c:2636 4 locks held by syz-executor/11628: #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88803cafd878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ec05258 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/11687: #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803595e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88805e2be078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880297b71e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ec05258 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 1 lock held by syz-executor/11808: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3505 1 lock held by syz-executor/11890: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3505 1 lock held by syz-executor/11903: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/11926: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/11932: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/11938: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/11952: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4150 1 lock held by syz-executor/11972: #0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f390178 (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: 7176 Comm: syz.2.380 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:check_preemption_disabled+0x22/0xe0 lib/smp_processor_id.c:53 Code: 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 87 0d 45 07 65 8b 0d 7c 0d 45 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d 59 aa 03 00 cc 9c 59 f7 c1 00 02 00 00 74 ea 65 4c 8b 3d 2e 0d RSP: 0018:ffffc90004f67af8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffc90004f67d70 RCX: 0000000080000001 RDX: 0000000000000002 RSI: ffffffff8baa2960 RDI: ffffffff8baa2920 RBP: ffffc90004f67cd0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90004f67d70 R11: fffff520009ecfb1 R12: 0000000000000000 R13: ffffffff825643cb R14: ffff888034ff37a0 R15: 0000000000000001 FS: 00007f4e240cd6c0(0000) GS:ffff888125ecd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557e4f00bd08 CR3: 0000000059fe0000 CR4: 00000000003526f0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752 rcu_read_unlock include/linux/rcupdate.h:867 [inline] reverse_path_check fs/eventpoll.c:1693 [inline] ep_insert+0xc8a/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: 0033:0x7f4e25e9ce59 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:00007f4e240cd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9 RAX: ffffffffffffffda RBX: 00007f4e26116090 RCX: 00007f4e25e9ce59 RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000006 RBP: 00007f4e25f32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4e26116128 R14: 00007f4e26116090 R15: 00007ffffb52ec28