INFO: task syz.2.504:7336 blocked for more than 154 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.504 state:D stack:25768 pid:7336 ppid:5769 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 dev_ioctl+0x83c/0x1140 net/core/dev_ioctl.c:794 sock_ioctl+0x74c/0x7e0 net/socket.c:1265 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3d0839c819 RSP: 002b:00007f3d0928c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3d08615fa0 RCX: 00007f3d0839c819 RDX: 0000200000000080 RSI: 00000000000089f1 RDI: 0000000000000009 RBP: 00007f3d08432c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3d08616038 R14: 00007f3d08615fa0 R15: 00007ffd30ae8468 INFO: task syz.0.507:7341 blocked for more than 155 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.507 state:D stack:25840 pid:7341 ppid:5770 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 register_nexthop_notifier+0x88/0x240 net/ipv4/nexthop.c:3636 ops_init+0x397/0x640 net/core/net_namespace.c:139 setup_net+0x3b6/0xa30 net/core/net_namespace.c:343 copy_net_ns+0x36d/0x5e0 net/core/net_namespace.c:520 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 copy_namespaces+0x430/0x4a0 kernel/nsproxy.c:179 copy_process+0x1724/0x3d80 kernel/fork.c:2510 kernel_clone+0x24b/0x8a0 kernel/fork.c:2915 __do_sys_clone kernel/fork.c:3058 [inline] __se_sys_clone kernel/fork.c:3042 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3042 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6e4619c819 RSP: 002b:00007f6e47012fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f6e46415fa0 RCX: 00007f6e4619c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000041064400 RBP: 00007f6e46232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f6e46416038 R14: 00007f6e46415fa0 R15: 00007ffc3c7e4d18 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/0:2/788: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90003837d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003837d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u4:8/1327: #0: ffff88802c69dd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88802c69dd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90004abfd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90004abfd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4718 2 locks held by getty/5529: #0: ffff888031ab20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 3 locks held by kworker/1:6/5866: #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90004c1fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90004c1fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x92/0xd90 net/wireless/reg.c:2463 4 locks held by syz.3.498/7317: 1 lock held by syz.2.504/7336: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x83c/0x1140 net/core/dev_ioctl.c:794 2 locks held by syz.0.507/7341: #0: ffffffff8e3b5710 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516 #1: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x88/0x240 net/ipv4/nexthop.c:3636 1 lock held by syz.1.511/7355: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7357: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7370: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7373: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7378: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7381: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7385: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7389: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7392: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7403: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7409: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 1 lock held by syz-executor/7412: #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c2748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6472 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7317 Comm: syz.3.498 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215 Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 1c f5 03 0d 48 89 de 5b e9 e3 67 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d b0 93 7c 7e 65 8b 15 b1 93 7c 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc90000007878 EFLAGS: 00000046 RAX: ffffffff81ae3245 RBX: 0000000000000000 RCX: ffff88802eaabc00 RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007970 R08: ffffffff8e8b14ef R09: 1ffffffff1d1629d R10: dffffc0000000000 R11: fffffbfff1d1629e R12: ffffc90000007b80 R13: dffffc0000000000 R14: 0000000000000000 R15: 000000000048068b FS: 00007fc221b466c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2743f47e20 CR3: 000000007bc43000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_prepare_sample+0x12d5/0x1df0 kernel/events/core.c:7890 __perf_event_output kernel/events/core.c:7974 [inline] perf_event_output_forward+0x187/0x3e0 kernel/events/core.c:7995 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_event_overflow kernel/events/core.c:9741 [inline] perf_swevent_hrtimer+0x439/0x610 kernel/events/core.c:11230 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x4e1/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5255 Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 00 99 32 09 e8 9b 29 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90004b8ec98 EFLAGS: 00000282 RAX: 19b03611719dd100 RBX: 0000000000000000 RCX: 19b03611719dd100 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60 RBP: ffffc90004b8ecf0 R08: ffffffff911c552f R09: 1ffffffff2238aa5 R10: dffffc0000000000 R11: fffffbfff2238aa6 R12: ffff88802eaabc00 R13: dffffc0000000000 R14: ffff88801a27da00 R15: ffff8880b8e3cac8 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x155b/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x111/0x120 kernel/locking/spinlock.c:194 rcu_report_unblock_qs_rnp kernel/rcu/tree.c:1996 [inline] rcu_preempt_deferred_qs_irqrestore+0xa1c/0xce0 kernel/rcu/tree_plugin.h:560 rcu_read_unlock_special+0x3d4/0x4d0 kernel/rcu/tree_plugin.h:762 __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:818 [inline] page_ext_put+0x95/0xb0 mm/page_ext.c:533 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 kmem_cache_zalloc include/linux/slab.h:711 [inline] __kernfs_new_node+0xe5/0x810 fs/kernfs/dir.c:624 kernfs_new_node+0x14c/0x260 fs/kernfs/dir.c:700 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1068 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:294 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x434/0xd10 fs/sysfs/group.c:152 internal_create_groups fs/sysfs/group.c:192 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:218 device_add_groups drivers/base/core.c:2785 [inline] device_add_attrs+0x1b2/0x830 drivers/base/core.c:2905 device_add+0x528/0xc20 drivers/base/core.c:3637 netdev_register_kobject+0x188/0x320 net/core/net-sysfs.c:2042 register_netdevice+0x12ee/0x1bb0 net/core/dev.c:10318 ppp_unit_register drivers/net/ppp/ppp_generic.c:1229 [inline] ppp_dev_configure+0x84b/0xad0 drivers/net/ppp/ppp_generic.c:1285 ppp_create_interface drivers/net/ppp/ppp_generic.c:3362 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1070 [inline] ppp_ioctl+0x6e2/0x1a90 drivers/net/ppp/ppp_generic.c:743 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc220b9c819 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:00007fc221b46028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc220e15fa0 RCX: 00007fc220b9c819 RDX: 000000110e22fff6 RSI: 00000000c004743e RDI: 0000000000000005 RBP: 00007fc220c32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc220e16038 R14: 00007fc220e15fa0 R15: 00007ffd746c8808