INFO: task syz-executor:30577 blocked for more than 143 seconds. Tainted: G U 6.16.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24824 pid:30577 tgid:30577 ppid:1 task_flags:0x480140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116 __debugfs_file_removed fs/debugfs/inode.c:775 [inline] remove_one+0x312/0x420 fs/debugfs/inode.c:782 simple_recursive_removal+0x21b/0x690 fs/libfs.c:636 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:805 nsim_dev_debugfs_exit drivers/net/netdevsim/dev.c:367 [inline] nsim_drv_remove+0xd2/0x1d0 drivers/net/netdevsim/dev.c:1679 device_remove+0xcb/0x170 drivers/base/dd.c:567 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1295 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579 device_del+0x396/0x9f0 drivers/base/core.c:3881 device_unregister+0x1d/0xc0 drivers/base/core.c:3922 nsim_bus_dev_del drivers/net/netdevsim/bus.c:462 [inline] del_device_store+0x355/0x4a0 drivers/net/netdevsim/bus.c:226 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efd56d8d45f RSP: 002b:00007ffe6c5343b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007efd56d8d45f RDX: 0000000000000001 RSI: 00007ffe6c534400 RDI: 0000000000000005 RBP: 00007efd56e11fbd R08: 0000000000000000 R09: 00007ffe6c534207 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe6c534400 R14: 00007efd57ae4620 R15: 0000000000000003 INFO: task syz.4.4807:30737 blocked for more than 144 seconds. Tainted: G U 6.16.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4807 state:D stack:26888 pid:30737 tgid:30736 ppid:29485 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 nsim_bus_dev_max_vfs_write+0x206/0x410 drivers/net/netdevsim/dev.c:275 full_proxy_write+0x13f/0x200 fs/debugfs/file.c:398 vfs_write+0x29d/0x1150 fs/read_write.c:684 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee8e38e9a9 RSP: 002b:00007fee8f2c4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fee8e5b5fa0 RCX: 00007fee8e38e9a9 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007fee8e410d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fee8e5b5fa0 R15: 00007ffc87482158 INFO: task syz.0.4815:30800 blocked for more than 144 seconds. Tainted: G U 6.16.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.4815 state:D stack:26888 pid:30800 tgid:30799 ppid:30286 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:884 [inline] open_last_lookups fs/namei.c:3815 [inline] path_openat+0x818/0x2cb0 fs/namei.c:4052 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8add38e9a9 RSP: 002b:00007f8ade130038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8add5b5fa0 RCX: 00007f8add38e9a9 RDX: 0000000000048002 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f8add410d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8add5b5fa0 R15: 00007ffce96ac248 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 6 locks held by kworker/u11:15/26568: #0: ffff88801c6fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9001092fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90349e50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662 #3: ffffffff9035fea8 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1b/0x230 drivers/net/wireguard/device.c:417 #4: ffff88805f2954e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_pre_exit+0xdd/0x230 drivers/net/wireguard/device.c:422 #5: ffffffff8e5d0278 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304 2 locks held by getty/29320: #0: ffff88814ca860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ec62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 7 locks held by syz-executor/30577: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff8880329d6c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 #4: ffff88803054f0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff88803054f0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff88803054f0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292 #5: ffff888030549250 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1675 #6: ffff888059498148 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #6: ffff888059498148 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: simple_recursive_removal+0x2c5/0x690 fs/libfs.c:628 3 locks held by syz.4.4807/30737: #0: ffff888029987978 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1217 #1: ffff88801faec428 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff888030549250 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_bus_dev_max_vfs_write+0x206/0x410 drivers/net/netdevsim/dev.c:275 2 locks held by syz.0.4815/30800: #0: ffff88801faec428 (sb_writers#8){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:3805 [inline] #0: ffff88801faec428 (sb_writers#8){.+.+}-{0:0}, at: path_openat+0x1ec8/0x2cb0 fs/namei.c:4052 #1: ffff888059498148 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline] #1: ffff888059498148 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: open_last_lookups fs/namei.c:3815 [inline] #1: ffff888059498148 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: path_openat+0x818/0x2cb0 fs/namei.c:4052 4 locks held by syz-executor/30835: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88802921cc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30863: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff888033907888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30892: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88805bc57888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30905: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff888033525488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30916: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88805c94cc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30935: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88805be21c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30948: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88805b547888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/30961: #0: ffff88807ecd0428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88805c94c488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880286470f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e7ce8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.16.0-rc7-syzkaller #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245