INFO: task syz.3.3126:19471 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3126 state:D stack:26072 pid:19471 tgid:19470 ppid:16218 task_flags:0x480140 flags:0x00080006 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 __debugfs_file_removed fs/debugfs/inode.c:751 [inline] remove_one+0x312/0x420 fs/debugfs/inode.c:758 __simple_recursive_removal+0x148/0x5c0 fs/libfs.c:625 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:781 nsim_dev_health_exit+0x3b/0xe0 drivers/net/netdevsim/health.c:227 nsim_dev_reload_destroy+0x144/0x4a0 drivers/net/netdevsim/dev.c:1767 nsim_drv_remove+0x52/0x1e0 drivers/net/netdevsim/dev.c:1779 device_remove+0xcb/0x180 drivers/base/dd.c:631 __device_release_driver drivers/base/dd.c:1344 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1367 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657 device_del+0x376/0x9b0 drivers/base/core.c:3879 device_unregister+0x1d/0xe0 drivers/base/core.c:3920 nsim_bus_dev_del drivers/net/netdevsim/bus.c:491 [inline] del_device_store+0x346/0x480 drivers/net/netdevsim/bus.c:244 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd95c99c819 RSP: 002b:00007fd95d7d8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd95cc15fa0 RCX: 00007fd95c99c819 RDX: 0000000000000045 RSI: 0000200000000040 RDI: 0000000000000006 RBP: 00007fd95ca32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd95cc16038 R14: 00007fd95cc15fa0 R15: 00007ffdaa2bca78 INFO: task syz.0.3129:19487 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.3129 state:D stack:27176 pid:19487 tgid:19485 ppid:16463 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 devlink_health_report+0x681/0xb50 net/devlink/health.c:680 nsim_dev_health_break_write+0x166/0x210 drivers/net/netdevsim/health.c:162 full_proxy_write+0x135/0x1a0 fs/debugfs/file.c:388 vfs_write+0x2aa/0x1070 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f92c899c819 RSP: 002b:00007f92c9906028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f92c8c15fa0 RCX: 00007f92c899c819 RDX: 00000000000001e1 RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007f92c8a32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f92c8c16038 R14: 00007f92c8c15fa0 R15: 00007ffee9b60448 INFO: task syz-executor:19694 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24552 pid:19694 tgid:19694 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd9c6f5d04e RSP: 002b:00007ffec33dfe88 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055556a56a500 RCX: 00007fd9c6f5d04e RDX: 0000000000000001 RSI: 00007ffec33dff10 RDI: 0000000000000005 RBP: 00007fd9c7033514 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffec33dff10 R14: 00007fd9c7d44620 R15: 0000000000000003 INFO: task syz-executor:19711 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-executor state:D stack:24712 pid:19711 tgid:19711 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1ce4d5d04e RSP: 002b:00007ffdef479568 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055556a8c3500 RCX: 00007f1ce4d5d04e RDX: 0000000000000001 RSI: 00007ffdef4795f0 RDI: 0000000000000005 RBP: 00007f1ce4e33514 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdef4795f0 R14: 00007f1ce5b44620 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/32: #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/12744: #0: ffff8880339ae0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90003b392f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:5/16193: #0: ffff88813fe63148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263 #1: ffffc90004257d08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264 #2: ffffffff8e7f3000 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 2 locks held by kworker/u10:25/18537: #0: ffff88801ebef948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263 #1: ffffc90004d1fd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264 3 locks held by kworker/u10:27/18539: #0: ffff88801c6b6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263 #1: ffffc90004ddfd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264 #2: ffffffff8e7f3000 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 8 locks held by syz.3.3126/19471: #0: ffff88802071f7b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1261 #1: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #2: ffff88807a59a888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #3: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #3: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #4: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 #5: ffff8880796ba130 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #5: ffff8880796ba130 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline] #5: ffff8880796ba130 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1364 #6: ffff88807dbf2250 (&devlink->lock_key#9){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1e0 drivers/net/netdevsim/dev.c:1778 #7: ffff8880603dcb58 (&sb->s_type->i_mutex_key#10/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #7: ffff8880603dcb58 (&sb->s_type->i_mutex_key#10/2){+.+.}-{4:4}, at: __simple_recursive_removal+0xe0/0x5c0 fs/libfs.c:621 3 locks held by syz.0.3129/19487: #0: ffff8880337020f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1261 #1: ffff8880202e0420 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #2: ffff88807dbf2250 (&devlink->lock_key#9){+.+.}-{4:4}, at: devlink_health_report+0x681/0xb50 net/devlink/health.c:680 4 locks held by syz-executor/19694: #0: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #1: ffff888065e1a888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #3: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/19711: #0: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #1: ffff888060482488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #3: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/20359: #0: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #1: ffff888029b1a088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #3: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/20376: #0: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #1: ffff88802bb2f888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #3: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/21062: #0: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #1: ffff8880b3725488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #3: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/21074: #0: ffff8880376e8420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740 #1: ffff888020b93088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028e55b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344 #3: ffffffff8fb6f088 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245