INFO: task syz.9.1268:11530 blocked for more than 145 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1268 state:D stack:26048 pid:11530 tgid:11527 ppid:8082 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
sync_bdevs+0x294/0x480 block/bdev.c:1378
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x00007efd4319fb19
RSP: 002b:00007efd44098028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007efd43426090 RCX: 00007efd4319fb19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007efd43426090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efd43426128 R14: 00007efd43426090 R15: 00007ffdf5f43b88
Showing all locks held in the system:
locks held by ksoftirqd/0/16: 1, last CPU#0:
#0: ffff8880b8228618 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:2083 [inline]
#0: ffff8880b8228618 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2136
locks held by rcu_tasks_kthre/31: 1, on CPU#1:
#0: ffffffff9015af08 (rcu_tasks.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xb1f/0xe20 kernel/rcu/tasks.h:620
locks held by khungtaskd/35: 1, last CPU#1:
#0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:8/995: 6, on CPU#1:
#0: ffff88801d68e150 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801d68e150 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801d68e150 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline]
#0: ffff88801d68e150 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588
#1: ffffc90004df7c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004df7c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004df7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline]
#1: ffffc90004df7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588
#2: ffffffff91689ce8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:679
#3: ffff88807e50e128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff88807e50e128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff88807e50e128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x122/0x560 net/devlink/core.c:581
#4: ffff888020e9d258 (&devlink->lock_key#22){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:314 [inline]
#4: ffff888020e9d258 (&devlink->lock_key#22){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff888020e9d258 (&devlink->lock_key#22){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x138/0x560 net/devlink/core.c:581
#5: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: unreg
#5: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:4072
locks held by getty/5394: 2, on CPU#0:
#0: ffff8880373860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032362e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz.0.800/9224: 1, last CPU#1:
#0: ffff8880555d6480 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: process_measurement+0x7d0/0x1c10 security/integrity/ima/ima_main.c:319
locks held by udevd/10128: 1, on CPU#1:
#0: ffff8880285a5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by kworker/u8:19/10358: 3, last CPU#1:
#0: ffff88813fe54150 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe54150 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe54150 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline]
#0: ffff88813fe54150 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588
#1: ffffc9000390fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000390fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000390fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline]
#1: ffffc9000390fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588
#2: ffff88802c0ff258 (&devlink->lock_key#9){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834
locks held by udevd/10582: 1, on CPU#1:
#0: ffff888028771350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz.9.1268/11530: 1, on CPU#0:
#0: ffff888028771350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x294/0x480 block/bdev.c:1378
locks held by syz-executor/12361: 7, on CPU#1:
#0: ffff8880376d8478 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2762 [inline]
#0: ffff8880376d8478 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#1: ffff888045dc8c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
#2: ffff88802a82e008 (kn->active#51){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88802a82e008 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
#3: ffffffff90ef02e0 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff88802c954128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88802c954128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1046 [inline]
#4: ffff88802c954128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa9/0x7d0 drivers/base/dd.c:1377
#5: ffff88802c955258 (&devlink->lock_key#23){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1724
#6: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1222
locks held by syz-executor/12407: 2, on CPU#1:
#0: ffffffff90dde108 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff90dde108 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff90dde108 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:598
#1: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#1: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc1d/0x1c30 net/core/rtnetlink.c:4251
locks held by syz-executor/12450: 4, last CPU#0:
#0: ffffffff90dde108 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff90dde108 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff90dde108 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:598
#1: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#1: ffffffff916989e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc1d/0x1c30 net/core/rtnetlink.c:4251
#2: ffffffff902b2e90 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:213 [inline]
#2: ffffffff902b2e90 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:320
#3: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#3: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.6.1419/12662: 1, last CPU#0:
#0: ffff88803447e540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:548 [inline]
#0: ffff88803447e540 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d5/0xa40 mm/mmap.c:1323
locks held by rm/12666: 1, last CPU#0:
#0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: path_init+0x124/0x1300 fs/namei.c:2695
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
watchdog+0x1073/0x10f0 kernel/hung_task.c:598
kthread+0x38b/0x480 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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:425
Code: e8 3e e4 3f fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 2f ae b9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 ca 39 85 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000aa78b8 EFLAGS: 00000002
RAX: 1ffffffff3843d00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85894f90 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9c21ef80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881234f0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff247f290a0 CR3: 0000000070288000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:134 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2036
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3294 [inline]
__serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3369
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3520
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 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