INFO: task syz.2.1591:12229 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1591      state:D stack:28728 pid:12229 tgid:12228 ppid:5602   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xcbf/0x1bc0 kernel/locking/mutex.c:821
 class_mutex_constructor include/linux/mutex.h:253 [inline]
 ptmx_open drivers/tty/pty.c:800 [inline]
 ptmx_open+0x11a/0x360 drivers/tty/pty.c:767
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f827599e0d9
RSP: 002b:00007f8276825028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8275c25fa0 RCX: 00007f827599e0d9
RDX: 0000000000000002 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f8275a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8275c26038 R14: 00007f8275c25fa0 R15: 00007ffdff3ca9c8
 </TASK>
INFO: task syz.4.1608:12314 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1608      state:D stack:28480 pid:12314 tgid:12312 ppid:6975   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xcbf/0x1bc0 kernel/locking/mutex.c:821
 tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f91bb79e0d9
RSP: 002b:00007f91bc65a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f91bba25fa0 RCX: 00007f91bb79e0d9
RDX: 0000000000020000 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f91bb835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f91bba26038 R14: 00007f91bba25fa0 R15: 00007ffd1b3e13e8
 </TASK>

Showing all locks held in the system:
locks held by pool_workqueue_/3: 1, last CPU#0:
 #0: ffffffff8edf5ce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
locks held by kworker/u8:1/13: 2, on CPU#0:
 #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90000127d08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
locks held by khungtaskd/31: 1, last CPU#0:
 #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6793
locks held by kworker/u8:2/42: 2, last CPU#0:
 #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90000b27d08 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
locks held by kworker/u8:3/48: 2, last CPU#0:
 #0: ffff8880336fa140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90000b87d08 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
locks held by kworker/u8:9/3340: 3, on CPU#0:
 #0: ffff88803347a940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc9000e6afd08 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
 #2: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
 #2: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4230
locks held by getty/5352: 2, on CPU#1:
 #0: ffff8880336660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by kworker/0:4/5604: 3, on CPU#0:
 #0: ffff88801c057140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90002ef7d08 (netdev_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
 #2: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x71/0x880 net/core/netdev_work.c:132
locks held by kworker/0:7/5705: 3, on CPU#0:
 #0: ffff88801c057140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90003bdfd08 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
 #2: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
locks held by kworker/0:9/7404: 2, last CPU#0:
 #0: ffff888034ea5940 ((wq_completion)wg-crypt-wg2#4){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc9000392fd08 ((work_completion)(&({ do { const void __seg_gs *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
locks held by syz.3.1559/12089: 4, last CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
 #1: ffff88802b01c1b0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x39/0x470 drivers/tty/tty_io.c:1379
 #2: ffffffff8edd6040 (console_lock){+.+.}-{0:0}, at: class_console_lock_constructor include/linux/console.h:734 [inline]
 #2: ffffffff8edd6040 (console_lock){+.+.}-{0:0}, at: con_install+0x99/0x620 drivers/tty/vt/vt.c:3743
 #3: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #3: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #3: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline]
 #3: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: console_flush_one_record+0xfd/0xf10 kernel/printk/printk.c:3246
locks held by syz.2.1591/12229: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:800 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0x11a/0x360 drivers/tty/pty.c:767
locks held by kworker/u8:10/12254: 3, on CPU#0:
 #0: ffff88801d2d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90004f67d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
 #2: ffffffff90cabc68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:677
locks held by syz.4.1608/12314: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
locks held by syz.6.1619/12370: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
locks held by syz.8.1652/12594: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:800 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0x11a/0x360 drivers/tty/pty.c:767
locks held by syz.1.1653/12601: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
locks held by kworker/u8:11/12606: 3, on CPU#0:
 #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc900000f7d08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
 #2: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
locks held by syz.7.1662/12667: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:800 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0x11a/0x360 drivers/tty/pty.c:767
locks held by syz.5.1668/12725: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
locks held by syz.5.1668/12729: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
locks held by krxrpcio/7001/12751: 1, last CPU#0:
 #0: ffff88807c3b6e60 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
 #0: ffff88807c3b6e60 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: udpv6_destroy_sock+0x1c/0x280 net/ipv6/udp.c:1794
locks held by syz-executor/12819: 1, on CPU#0:
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xac3/0x2620 net/core/rtnetlink.c:4214
locks held by syz.9.1681/12910: 1, on CPU#0:
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline]
 #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093
locks held by syz-executor/12954: 1, on CPU#0:
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xac3/0x2620 net/core/rtnetlink.c:4214
locks held by syz-executor/12963: 2, last CPU#0:
 #0: ffffffff91464808 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
 #0: ffffffff91464808 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline]
 #0: ffffffff91464808 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:599
 #1: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #1: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xac3/0x2620 net/core/rtnetlink.c:4214
locks held by syz-executor/12994: 1, on CPU#0:
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xac3/0x2620 net/core/rtnetlink.c:4214
locks held by syz.0.1687/13019: 1, on CPU#0:
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
 #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3587
locks held by sed/13036: 1, last CPU#0:
 #0: ffff888034411d38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #0: ffff888034411d38 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __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:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>