INFO: task syz-executor.2:4886 blocked for more than 143 seconds. Not tainted 6.1.81-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27560 pid:4886 ppid:3590 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747 blkdev_put+0x100/0x750 block/bdev.c:913 blkdev_close+0x56/0x80 block/fops.c:514 __fput+0x3b7/0x890 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb6c8c7dda9 RSP: 002b:00007fb6c9a760c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fb6c8dabf80 RCX: 00007fb6c8c7dda9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007fb6c8cca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fb6c8dabf80 R15: 00007fff7b49f948 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d12aa10 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d12b210 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516 1 lock held by khungtaskd/28: #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:319 [inline] #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:760 [inline] #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494 1 lock held by udevd/3001: 2 locks held by getty/3298: #0: ffff88814af4b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188 1 lock held by udevd/3598: #0: ffff8880208334c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x148/0xa10 block/bdev.c:815 3 locks held by kworker/u4:5/3688: 4 locks held by kworker/u4:6/3692: 1 lock held by syz-executor.2/4886: #0: ffff8880208334c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x750 block/bdev.c:913 2 locks held by syz-executor.4/9220: 3 locks held by syz-executor.1/9240: 4 locks held by syz-executor.0/9241: #0: ffff888076a2c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffff888055a310b8 (&buf->lock){+.+.}-{3:3}, at: tiocsti+0x1d4/0x2f0 drivers/tty/tty_io.c:2286 #2: ffff888076a2c2e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_receive_buf_common+0x7a/0x1410 drivers/tty/n_tty.c:1674 #3: ffffc90014acd380 (&ldata->output_lock){+.+.}-{3:3}, at: flush_echoes drivers/tty/n_tty.c:815 [inline] #3: ffffc90014acd380 (&ldata->output_lock){+.+.}-{3:3}, at: __receive_buf drivers/tty/n_tty.c:1615 [inline] #3: ffffc90014acd380 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_receive_buf_common+0xcc4/0x1410 drivers/tty/n_tty.c:1711 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.81-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3692 Comm: kworker/u4:6 Not tainted 6.1.81-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: netns cleanup_net RIP: 0010:node_maxindex lib/radix-tree.c:216 [inline] RIP: 0010:radix_tree_load_root lib/radix-tree.c:395 [inline] RIP: 0010:__radix_tree_lookup lib/radix-tree.c:756 [inline] RIP: 0010:radix_tree_delete_item+0x85/0x3e0 lib/radix-tree.c:1418 Code: bf 02 00 00 00 48 89 de e8 e8 9b 07 f7 48 83 fb 02 0f 85 f4 02 00 00 4c 89 ed 48 83 e5 fd 48 89 e8 48 c1 e8 03 42 0f b6 04 30 <84> c0 0f 85 88 01 00 00 0f b6 6d 00 bf 40 00 00 00 89 ee e8 33 9a RSP: 0018:ffffc900052ef660 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff888022439dc0 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000002 RBP: ffff888012906680 R08: ffffffff8a82e708 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff88802864d0a0 R13: ffff888012906682 R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e821000 CR3: 000000007da2e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_put+0x2f2/0x4a0 fs/kernfs/dir.c:560 sysfs_remove_groups+0x50/0xa0 fs/sysfs/group.c:312 device_remove_groups drivers/base/core.c:2733 [inline] device_remove_attrs+0x1d8/0x290 drivers/base/core.c:2947 device_del+0x6da/0xbd0 drivers/base/core.c:3858 unregister_netdevice_many+0x12c1/0x17a0 net/core/dev.c:10905 sit_exit_batch_net+0x43c/0x480 net/ipv6/sit.c:1887 ops_exit_list net/core/net_namespace.c:174 [inline] cleanup_net+0x763/0xb60 net/core/net_namespace.c:601 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307