INFO: task syz.8.602:8782 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.602       state:D stack:22376 pid:8782  tgid:8779  ppid:8267   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:293 [inline]
 __down_common+0x3b7/0x850 kernel/locking/semaphore.c:318
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 console_lock+0x58/0x90 kernel/printk/printk.c:2896
 class_console_lock_constructor include/linux/console.h:734 [inline]
 con_install+0x97/0x770 drivers/tty/vt/vt.c:3743
 tty_driver_install_tty drivers/tty/tty_io.c:1295 [inline]
 tty_init_dev+0xd7/0x4d0 drivers/tty/tty_io.c:1407
 tty_open_by_driver drivers/tty/tty_io.c:2073 [inline]
 tty_open+0x7d9/0xcc0 drivers/tty/tty_io.c:2120
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e44/0x3830 fs/namei.c:4863
 do_file_open+0x23e/0x4a0 fs/namei.c:4892
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f95b535e6ce
RSP: 002b:00007f95b61ceb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f95b61cf6c0 RCX: 00007f95b535e6ce
RDX: 0000000000000002 RSI: 00007f95b61cec00 RDI: ffffffffffffff9c
RBP: 00007f95b5433eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f95b5626038 R14: 00007f95b5625fa0 R15: 00007ffc075404e8
 </TASK>
INFO: task syz.7.625:8885 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.625       state:D stack:28424 pid:8885  tgid:8883  ppid:7893   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
 tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e44/0x3830 fs/namei.c:4863
 do_file_open+0x23e/0x4a0 fs/namei.c:4892
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8b7f5e6ce
RSP: 002b:00007fc8b61f5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc8b61f66c0 RCX: 00007fc8b7f5e6ce
RDX: 0000000000000002 RSI: 00007fc8b61f5c00 RDI: ffffffffffffff9c
RBP: 00007fc8b8033eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8b8226038 R14: 00007fc8b8225fa0 R15: 00007ffe201a5c88
 </TASK>
INFO: task syz.7.625:8886 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.625       state:D stack:28424 pid:8886  tgid:8883  ppid:7893   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:293 [inline]
 __down_common+0x3b7/0x850 kernel/locking/semaphore.c:318
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 console_lock+0x58/0x90 kernel/printk/printk.c:2896
 class_console_lock_constructor include/linux/console.h:734 [inline]
 vcs_open+0x61/0xd0 drivers/tty/vt/vc_screen.c:746
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e44/0x3830 fs/namei.c:4863
 do_file_open+0x23e/0x4a0 fs/namei.c:4892
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8b7f9de99
RSP: 002b:00007fc8b61d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc8b8226090 RCX: 00007fc8b7f9de99
RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007fc8b8033eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8b8226128 R14: 00007fc8b8226090 R15: 00007ffe201a5c88
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:2/36:
3 locks held by kworker/u8:5/82:
3 locks held by kworker/u8:11/3353:
 #0: ffff888031e3d140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff888031e3d140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc9000d887c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc9000d887c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #2: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4229
2 locks held by getty/5379:
 #0: ffff888035ab70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:3/5636:
3 locks held by kworker/u8:12/6607:
 #0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801b064140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc900051d7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc900051d7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #2: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by syz.1.470/8097:
2 locks held by syz.8.602/8782:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
 #1: ffff888076f2b1b0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1406
1 lock held by syz.7.625/8885:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz.6.671/9138:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:800
1 lock held by syz.0.673/9156:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz.2.677/9230:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
3 locks held by kworker/u8:13/9353:
1 lock held by syz.3.684/9368:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz.4.689/9476:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz.8.726/9921:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz.7.743/9996:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz.7.743/10015:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:800
1 lock held by syz.5.750/10033:
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
 #0: ffffffff8f458480 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120
1 lock held by syz-executor/10064:
 #0: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978
9 locks held by syz-executor/10170:
1 lock held by syz-executor/10207:
 #0: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158
2 locks held by syz.1.790/10296:
2 locks held by syz.9.794/10305:
 #0: ffff888026c8d6e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2410
 #1: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff9002d340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14a0 net/core/rtnetlink.c:2562

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>