INFO: task syz-executor:7912 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20360 pid:7912 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 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+0x6b7/0xcc0 kernel/locking/mutex.c:747 rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 netdev_run_todo+0x2d2/0xd90 net/core/dev.c:10596 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x13f/0x1c0 drivers/net/tun.c:3511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff216fc2005 RSP: 002b:00007fff6de1ecd0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 0000000000000370 RCX: 00007ff216fc2005 RDX: 00007fff6de1ed10 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff6de1ed7c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000122 R13: 0000000000000060 R14: 00000000000e484b R15: 00007fff6de1edd0 INFO: task syz-executor:12751 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22280 pid:12751 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 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+0x6b7/0xcc0 kernel/locking/mutex.c:747 rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 netdev_run_todo+0x2d2/0xd90 net/core/dev.c:10596 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x13f/0x1c0 drivers/net/tun.c:3511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbe04d8e1ff RSP: 002b:00007ffd0ab2ca70 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: 0000000000000003 RBX: 0000000000000005 RCX: 00007fbe04d8e1ff RDX: 0000000000000003 RSI: 00007ffd0ab2cac0 RDI: 0000000000000005 RBP: 00007fbe04e152ef R08: 0000000000000000 R09: 00007ffd0ab2c8c7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 00007ffd0ab2cac0 R14: 00007fbe05b14620 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 4 locks held by kworker/u4:5/142: #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90002de7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90002de7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfa9250 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606 #3: ffffffff8cd35840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 2 locks held by getty/5531: #0: ffff88802d0cb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/7912: #0: ffffffff8cd35840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 2 locks held by kworker/u4:4/9778: 1 lock held by syz-executor/12748: #0: ffffffff8cd35840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 1 lock held by syz-executor/12751: #0: ffffffff8cd35840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 4 locks held by syz-executor/12918: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff8880318c9488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 7 locks held by syz-executor/12920: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff88807dd40488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 #4: ffff888023fee0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline] #4: ffff888023fee0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff888023fee0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb6/0x7a0 drivers/base/dd.c:1292 #5: ffff88807e5cc250 (&devlink->lock_key#7){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8cd35840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 4 locks held by syz-executor/12923: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff88807dd43c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz-executor/13290: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff88804c91e888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz-executor/13314: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff888054f5e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz-executor/13322: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff8880268f1888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz-executor/13510: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff88809192c088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz-executor/13513: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff888036dee088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz-executor/13519: #0: ffff88807ecb8418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #1: ffff88809193bc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881427972f0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209 4 locks held by syz.8.1864/13703: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x4c3/0x2970 arch/x86/kernel/unwind_orc.c:494 Code: 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 75 3e 4d 63 2f 4d 01 fd 4c 89 ef 4c 89 f6 e8 18 05 4b 00 49 8d 47 04 4d 39 f5 4c 0f 46 e0 <49> 8d 47 fc 48 0f 47 d8 49 0f 46 ef 49 39 dc 77 28 e8 e7 02 4b 00 RSP: 0018:ffffc90000007398 EFLAGS: 00000297 RAX: ffffffff8e5b87e4 RBX: ffffffff8e5b87e0 RCX: ffffffff8ca93440 RDX: 0000000000000100 RSI: ffffffff8161a02a RDI: ffffffff81619e48 RBP: ffffffff8e5b87e0 R08: ffffc90000007530 R09: 0000000000000017 R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8e5b87e4 R13: ffffffff81619e48 R14: ffffffff8161a02a R15: ffffffff8e5b87e0 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffe70 CR3: 000000003f048000 CR4: 00000000003506f0 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 __netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:717 netdev_alloc_skb include/linux/skbuff.h:3272 [inline] dev_alloc_skb include/linux/skbuff.h:3285 [inline] __ieee80211_beacon_get+0xe17/0x1600 net/mac80211/tx.c:5447 ieee80211_beacon_get_tim+0xb8/0x560 net/mac80211/tx.c:5569 ieee80211_beacon_get include/net/mac80211.h:5440 [inline] mac80211_hwsim_beacon_tx+0x3c7/0x780 drivers/net/wireless/virtual/mac80211_hwsim.c:2265 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:766 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:802 mac80211_hwsim_beacon+0xbb/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2295 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 2b 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2 RAX: d6c41a3d3b632900 RBX: ffffffff8161a02b RCX: d6c41a3d3b632900 RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc73a0 RBP: ffffffff8ca07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65 R10: dffffc0000000000 R11: ffffed10171c6d66 R12: ffffffff8e4a39e8 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952688 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1eb/0x510 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 rest_init+0x2e2/0x300 init/main.c:744 arch_call_rest_init+0xe/0x10 init/main.c:841 start_kernel+0x459/0x4e0 init/main.c:1086 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b