INFO: task syz.7.748:14179 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.748 state:D stack:27992 pid:14179 tgid:14169 ppid:13556 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] lock_rename fs/namei.c:3712 [inline] __start_renaming+0x148/0x410 fs/namei.c:3808 do_renameat2+0x399/0x8f0 fs/namei.c:6022 __do_sys_rename fs/namei.c:6090 [inline] __se_sys_rename fs/namei.c:6088 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:6088 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb9f9faf749 RSP: 002b:00007fb9f81f5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007fb9fa206090 RCX: 00007fb9f9faf749 RDX: 0000000000000000 RSI: 0000200000000780 RDI: 0000200000000200 RBP: 00007fb9fa033f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb9fa206128 R14: 00007fb9fa206090 R15: 00007ffead97d588 INFO: task syz.7.748:14180 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.748 state:D stack:28952 pid:14180 tgid:14169 ppid:13556 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] lock_rename fs/namei.c:3712 [inline] __start_renaming+0x148/0x410 fs/namei.c:3808 do_renameat2+0x399/0x8f0 fs/namei.c:6022 __do_sys_rename fs/namei.c:6090 [inline] __se_sys_rename fs/namei.c:6088 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:6088 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb9f9faf749 RSP: 002b:00007fb9f81d4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007fb9fa206180 RCX: 00007fb9f9faf749 RDX: 0000000000000000 RSI: 0000200000000440 RDI: 0000200000000340 RBP: 00007fb9fa033f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb9fa206218 R14: 00007fb9fa206180 R15: 00007ffead97d588 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/68: #0: ffff88802fb31138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88802fb31138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000153fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000153fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e8a5af8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e8a5af8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 8 locks held by kworker/u8:9/1123: 2 locks held by dhcpcd/5465: 2 locks held by getty/5560: #0: ffff88823bf228a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:18/6380: #0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000c59fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000c59fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff8880335be0d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff88804fe89568 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 5 locks held by syz.7.748/14171: 2 locks held by syz.7.748/14179: #0: ffff8880335be480 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804fcc22f8 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88804fcc22f8 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline] #1: ffff88804fcc22f8 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808 2 locks held by syz.7.748/14180: #0: ffff8880335be480 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804fcc22f8 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88804fcc22f8 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline] #1: ffff88804fcc22f8 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808 1 lock held by syz-executor/14370: #0: ffffffff8e8a5af8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e8a5af8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 6 locks held by syz-executor/14402: 4 locks held by syz-executor/14405: #0: ffff888035080480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888035080480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805c221478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888142f430f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888142f430f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e12c878 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 2 locks held by syz-executor/14434: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1123 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net RIP: 0010:__bfs kernel/locking/lockdep.c:1753 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x1822/0x2cf0 kernel/locking/lockdep.c:5237 Code: 00 0f 83 8a 01 00 00 4e 8b 24 fd 60 38 bb 94 ff c0 25 ff 0f 00 00 89 05 bc 1e 1f 13 4d 85 e4 0f 84 b2 01 00 00 49 8b 44 24 10 <48> 85 c0 0f 84 1c 0d 00 00 8b 0d a7 1e 1f 13 39 48 5c 0f 84 67 ff RSP: 0018:ffffc90004b4eeb8 EFLAGS: 00000082 RAX: ffffffff92658a50 RBX: 00000000000003cd RCX: ffffffff956e5aa8 RDX: ffffffff957ebba8 RSI: ffff8880267c2b10 RDI: 00000000000003cd RBP: 14f354afde8c8d86 R08: ffffc90004b4ee80 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff819cebf0 R12: ffffffff956e5aa8 R13: ffff8880267c2b10 R14: ffff8880267c1e40 R15: 00000000000004e3 FS: 0000000000000000(0000) GS:ffff888126def000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f13a132ee9c CR3: 00000000abf28000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] psi_write_begin+0xab/0x160 kernel/sched/psi.c:183 psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 psi_sched_switch kernel/sched/stats.h:225 [inline] __schedule+0x2497/0x5070 kernel/sched/core.c:6857 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 80 11 35 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 5a 90 16 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ff cf 38 09 cc 48 8d 3d 47 cb 41 RSP: 0018:ffffc90004b4f460 EFLAGS: 00000286 RAX: 42164e644eaaff00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000023ceb100 RSI: ffffffff8cfdefe4 RDI: ffffffff8b3f57e0 RBP: ffffffff823ae558 R08: ffffffff823ae558 R09: ffff88803e0a15b0 R10: dffffc0000000000 R11: fffffbfff1db66ef R12: 0000000000000000 R13: ffff88803e0a15b0 R14: 0000000000000001 R15: 0000000000000246 rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:44 [inline] find_next_child+0x38/0x250 fs/libfs.c:579 __simple_recursive_removal+0x10b/0x510 fs/libfs.c:609 debugfs_remove+0x5b/0x70 fs/debugfs/inode.c:781 nsim_dev_port_debugfs_exit drivers/net/netdevsim/dev.c:443 [inline] __nsim_dev_port_del+0x173/0x1b0 drivers/net/netdevsim/dev.c:1529 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1540 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1763 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:1038 devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1d9/0x3d0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x187/0x990 net/core/net_namespace.c:234 cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246