INFO: task kworker/0:9:5889 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:9 state:D stack:22400 pid:5889 tgid:5889 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events console_callback Call Trace: 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] console_callback+0x69/0x450 drivers/tty/vt/vt.c:3352 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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 INFO: task syz.2.274:6856 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.274 state:D stack:28000 pid:6856 tgid:6852 ppid:5635 task_flags:0x400040 flags:0x00080002 Call Trace: 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: 0033:0x7fd759b5e84e RSP: 002b:00007fd757df5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fd757df66c0 RCX: 00007fd759b5e84e RDX: 0000000000000002 RSI: 00007fd757df5c00 RDI: ffffffffffffff9c RBP: 00007fd759c3500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd759e26218 R14: 00007fd759e26180 R15: 00007fffa4386198 INFO: task syz.4.287:6912 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.287 state:D stack:28424 pid:6912 tgid:6909 ppid:5621 task_flags:0x400040 flags:0x00080002 Call Trace: 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 class_mutex_constructor include/linux/mutex.h:253 [inline] ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:800 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: 0033:0x7f10dd79e019 RSP: 002b:00007f10de6b1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f10dda25fa0 RCX: 00007f10dd79e019 RDX: 0000000000000000 RSI: 0000200000000140 RDI: ffffffffffffff9c RBP: 00007f10dd83500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f10dda26038 R14: 00007f10dda25fa0 R15: 00007ffd9f6a38b8 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 3 locks held by kworker/u9:0/50: #0: ffff8880532a0140 ((wq_completion)hci8){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880532a0140 ((wq_completion)hci8){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000ba7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000ba7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88803a854ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331 3 locks held by kworker/u8:5/78: #0: ffff88803262e940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88803262e940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000248fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000248fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4229 3 locks held by kworker/u8:7/148: #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: ffffc90002effc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90002effc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by getty/5378: #0: ffff8880366a90a0 (&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 4 locks held by kworker/0:5/5783: 2 locks held by kworker/0:9/5889: #0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004cdfc40 (console_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004cdfc40 (console_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 2 locks held by syz.2.274/6856: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 #1: ffff888051f261b0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1406 1 lock held by syz.4.287/6912: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:800 1 lock held by syz.0.315/7022: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:800 1 lock held by syz.3.341/7220: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.1.347/7251: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.1.347/7263: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.6.350/7318: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.9.361/7405: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.7.369/7456: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.8.377/7569: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz.4.404/7706: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 1 lock held by syz-executor/7821: #0: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 7 locks held by syz-executor/7832: #0: ffff888036b92450 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff888036b92450 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #1: ffff88801b02a480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336 #2: ffff8880295a52d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff8880295a52d8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337 #3: ffffffff8f8a9c80 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 #4: ffff888077fb3128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff888077fb3128 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #5: ffff888077fb2258 (&devlink->lock_key#18){+.+.}-{4:4}, at: nsim_drv_probe+0xfc/0xbf0 drivers/net/netdevsim/dev.c:1658 #6: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163 2 locks held by kworker/u8:22/7883: 1 lock held by syz.3.433/7920: #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8f458680 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0 drivers/tty/tty_io.c:2120 2 locks held by syz-executor/7989: #0: ffffffff8f778948 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f778948 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8f778948 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by syz-executor/8007: 1 lock held by syz-executor/8070: #0: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7082 2 locks held by dhcpcd-run-hook/8130: 2 locks held by syz.2.450/8133: #0: ffffffff9057d700 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff9057d700 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff9057d700 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff9002de40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 ============================================= 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: 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