INFO: task syz-executor.4:7736 blocked for more than 143 seconds. Not tainted 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:24880 pid:7736 tgid:7734 ppid:5102 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 rwsem_down_write_slowpath+0xeeb/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1af/0x200 kernel/locking/rwsem.c:1306 inode_lock_nested include/linux/fs.h:830 [inline] do_rmdir+0x263/0x580 fs/namei.c:4253 __do_sys_unlinkat fs/namei.c:4441 [inline] __se_sys_unlinkat fs/namei.c:4435 [inline] __x64_sys_unlinkat+0xe0/0xf0 fs/namei.c:4435 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd8cb87dea9 RSP: 002b:00007fd8cc5090c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007fd8cb9ac050 RCX: 00007fd8cb87dea9 RDX: 0000000000000200 RSI: 0000000020000140 RDI: ffffffffffffff9c RBP: 00007fd8cb8ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fd8cb9ac050 R15: 00007fff22458b78 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 3 locks held by kworker/1:2/780: #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90002effd00 (key_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90002effd00 (key_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8e33a0b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8e33a0b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x39a/0x820 kernel/rcu/tree_exp.h:939 4 locks held by kworker/u8:5/952: 2 locks held by getty/4838: #0: ffff88802aacf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by kworker/0:5/5163: #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90003ee7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90003ee7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/1:6/5165: #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc9000490fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc9000490fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 3 locks held by kworker/u8:9/5195: #0: ffff88802a412148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff88802a412148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90003f17d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90003f17d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4192 2 locks held by syz-executor.4/7735: 2 locks held by syz-executor.4/7736: #0: ffff88802e728420 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88805ca30188 (&type->i_mutex_dir_key#21/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:830 [inline] #1: ffff88805ca30188 (&type->i_mutex_dir_key#21/1){+.+.}-{3:3}, at: do_rmdir+0x263/0x580 fs/namei.c:4253 1 lock held by syz-executor.5/9151: #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592 1 lock held by syz-executor.2/9193: #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592 7 locks held by syz-executor.1/9433: #0: ffff88802a866420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2855 [inline] #0: ffff88802a866420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 #1: ffff88805a575088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888022d48f08 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8eee45e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 #4: ffff888060df00e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff888060df00e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1003 #5: ffff888060df1250 (&devlink->lock_key#21){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534 #6: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: fib_seq_sum+0x31/0x2a0 net/core/fib_notifier.c:46 1 lock held by syz-executor.0/9495: #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: __rtnl_newlink net/core/rtnetlink.c:3704 [inline] #0: ffffffff8f5a6a08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_newlink+0xab5/0x20a0 net/core/rtnetlink.c:3727 2 locks held by syz-executor.4/9539: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:380 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 952 Comm: kworker/u8:5 Not tainted 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: netns cleanup_net RIP: 0010:match_held_lock+0x77/0xb0 kernel/locking/lockdep.c:5231 Code: c7 c2 00 b4 c1 92 48 29 d0 48 c1 f8 03 48 ba 29 5c 8f c2 f5 28 5c 8f 48 0f af d0 bd 01 00 00 00 48 39 ca 74 02 31 ed 89 e8 5b <5d> e9 ae 0c 30 00 90 e8 dd c8 2b f9 85 c0 74 22 83 3d 92 f8 28 04 RSP: 0018:ffffc90003d97440 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff888020d6a8d8 RCX: ffff888020d69e00 RDX: ffff888020d69e00 RSI: ffffffff8f6b7998 RDI: ffff888020d6a8d8 RBP: 0000000000000000 R08: ffffffff89568868 R09: fffff520007b2e98 R10: dffffc0000000000 R11: fffff520007b2e98 R12: 0000000000000246 R13: ffff888020d69e00 R14: 00000000ffffffff R15: ffffffff8f6b7998 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32325000 CR3: 000000000e134000 CR4: 0000000000350ef0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5495 [inline] lock_is_held_type+0xa9/0x190 kernel/locking/lockdep.c:5825 lock_is_held include/linux/lockdep.h:231 [inline] neigh_flush_dev+0x1ab/0xae0 net/core/neighbour.c:393 __neigh_ifdown+0x45/0x400 net/core/neighbour.c:446 neigh_ifdown+0x1f/0x30 net/core/neighbour.c:464 rt6_disable_ip+0x816/0x890 net/ipv6/route.c:4910 addrconf_ifdown+0x15d/0x1bc0 net/ipv6/addrconf.c:3854 addrconf_notify+0x3cb/0x1020 notifier_call_chain+0x1a1/0x3e0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:1988 [inline] call_netdevice_notifiers net/core/dev.c:2002 [inline] unregister_netdevice_many_notify+0xd9b/0x16e0 net/core/dev.c:11105 cleanup_net+0x75d/0xcc0 net/core/net_namespace.c:632 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244