INFO: task syz-executor:1133 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:18088 pid:1133 tgid:1133 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 mutex_lock_nested+0x168/[ 2580.713724][ T37] __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] mutex_lock_nested+0x168/[ 2580.713724][ T37] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/[ 2580.713724][ T37] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 netdev_run_todo+0x2ff/0x10d0 net/core/dev.c:11717 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1102 [inline] nsim_create+0xf77/0x1160 drivers/net/netdevsim/netdev.c:1152 __nsim_dev_port_add+0x7f8/0xcd0 drivers/net/netdevsim/dev.c:1509 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1570 nsim_drv_probe+0x8d6/0xc00 drivers/net/netdevsim/dev.c:1731 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026 bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c7/0x450 drivers/base/dd.c:1098 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x12d/0x220 drivers/base/bus.c:620 device_add+0x7d7/0xb80 drivers/base/core.c:3772 nsim_bus_dev_new drivers/net/netdevsim/bus.c:471 [inline] new_device_store+0x37b/0x710 drivers/net/netdevsim/bus.c:191 kernfs_fop_write_iter+0x3a5/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 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: 0033:0x7f40f895e90e RSP: 002b:00007ffccffbd928 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055557879d500 RCX: 00007f40f895e90e RDX: 0000000000000003 RSI: 00007ffccffbd9b0 RDI: 0000000000000005 RBP: 00007f40f8a358cb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ffccffbd9b0 R14: 00007f40f9754620 R15: 0000000000000003 INFO: task syz.1.9654:1743 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.9654 state:D stack:21104 pid:1743 tgid:1741 ppid:31423 task_flags:0x40054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 netdev_run_todo+0x2ff/0x10d0 net/core/dev.c:11717 tun_detach drivers/net/tun.c:640 [inline] tun_chr_close+0x13f/0x1c0 drivers/net/tun.c:3442 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1009 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa4d153e0d9 RSP: 002b:00007fa4cf796028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fa4d17c5fa0 RCX: 00007fa4d153e0d9 RDX: 0000200000000040 RSI: 00000000400454ca RDI: 0000000000000003 RBP: 00007fa4d15d5024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa4d17c6038 R14: 00007fa4d17c5fa0 R15: 00007fffdd814568 Showing all locks held in the system: 2 locks held by rcuc/0/20: 5 locks held by ksoftirqd/1/30: 1 lock held by khungtaskd/37: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:4/67: 6 locks held by kworker/u8:6/158: 2 locks held by getty/5349: #0: ffff8880357960a0 (&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+0x460/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:16/5846: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000544fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000544fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 6 locks held by kworker/u8:3/16263: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90006507c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90006507c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5a3a40 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff8880346f1160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff8880346f1160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff8880346f1160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff8880359a2310 (&devlink->lock_key#19){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff8880359a2310 (&devlink->lock_key#19){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff8880359a2310 (&devlink->lock_key#19){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 #5: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 9 locks held by kworker/u8:20/16329: 1 lock held by syz-executor/31423: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1074: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 7 locks held by syz-executor/1133: #0: ffff88803461c500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803461c500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888061454878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff88802903db48 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802903db48 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee27338 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 #4: ffff888029f4c160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff888029f4c160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #5: ffff888026e1c310 (&devlink->lock_key#24){+.+.}-{4:4}, at: nsim_drv_probe+0xfc/0xc00 drivers/net/netdevsim/dev.c:1658 #6: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1592: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1620: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 4 locks held by syz-executor/1671: #0: ffff88803461c500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88803461c500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888031f2bc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff88802903da58 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802903da58 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee27338 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 1 lock held by syz.1.9654/1743: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1833: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1930: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1951: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/1978: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/2088: #0: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 2 locks held by syz-executor/2184: #0: ffffffff8ecedb48 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ecedb48 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ecedb48 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 3 locks held by syz-executor/2217: 2 locks held by syz-executor/2259: #0: ffffffff8fafc0a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8fafc0a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8fafc0a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by syz-executor/2373: #0: ffffffff8f5a3a40 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575 #1: ffffffff8f5b25f8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x820 net/ipv4/ip_tunnel.c:1149 1 lock held by syz.5.9871/2436: ============================================= 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 07/24/2026 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+0xfd7/0x1030 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: 2436 Comm: syz.5.9871 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320 Code: 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d a3 99 6b 04 00 <74> 1d 83 3d ba ab 6b 04 00 74 14 65 48 8b 0d 38 15 5a 07 31 c0 83 RSP: 0018:ffffc90004317608 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff823675ba RCX: ffff88802c2c5d00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8e1c30c0 R12: dffffc0000000000 R13: 0000000000000008 R14: 000000000006e5d1 R15: ffff88813ffe31a0 FS: 00007f24d52466c0(0000) GS:ffff888125d3e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdaab3a82b0 CR3: 000000007c21a000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock_sched include/linux/rcupdate.h:960 [inline] pfn_valid+0x32a/0x480 include/linux/mmzone.h:2280 page_table_check_set+0x25/0x530 mm/page_table_check.c:105 page_table_check_ptes_set include/linux/page_table_check.h:83 [inline] set_ptes include/linux/pgtable.h:447 [inline] set_pte_range+0x7ef/0x840 mm/memory.c:5588 finish_fault+0xd4b/0xff0 mm/memory.c:5724 do_read_fault mm/memory.c:5864 [inline] do_fault mm/memory.c:5994 [inline] do_pte_missing+0x1850/0x28f0 mm/memory.c:4566 handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault mm/memory.c:6517 [inline] handle_mm_fault+0xd28/0x13f0 mm/memory.c:6686 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x166b/0x2590 mm/gup.c:1428 populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860 __mm_populate+0x25f/0x390 mm/gup.c:1963 mm_populate include/linux/mm.h:4171 [inline] vm_mmap_pgoff+0x356/0x4e0 mm/util.c:586 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: 0033:0x7f24d6fee0d9 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:00007f24d5246028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f24d7275fa0 RCX: 00007f24d6fee0d9 RDX: 0000000002000001 RSI: 0000000000600000 RDI: 00002000009fd000 RBP: 00007f24d7085024 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000006031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f24d7276038 R14: 00007f24d7275fa0 R15: 00007ffe4621ed18