INFO: task syz.1.8:5985 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.8 state:D stack:26968 pid:5985 tgid:5951 ppid:5795 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline][ 232.591064][ T37] __schedule+0x1681/0x54c0
__schedule+0x1681/0x54c0 kernel/sched/core.c:7183[ 232.591064][ T37] __schedule+0x1681/0x54c0
__schedule_loop kernel/sched/core.c:7262 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7558
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1659 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1776
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1816
__rt_mutex_lock kernel/locking/rtmutex.c:1831 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:245
inode_lock include/linux/fs.h:1029 [inline]
open_last_lookups fs/namei.c:4608 [inline]
path_openat+0xb5e/0x38a0 fs/namei.c:4855
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4a7111c819
RSP: 002b:00007f4a6f355028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4a71396090 RCX: 00007f4a7111c819
RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f4a711b2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a71396128 R14: 00007f4a71396090 R15: 00007ffd7dbe4948
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
6 locks held by kworker/u8:1/13:
3 locks held by pr/legacy/17:
1 lock held by khungtaskd/37:
#0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:7/1016:
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
#1: ffffc90005bbfc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc90005bbfc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
7 locks held by kworker/u8:12/3541:
#0: ffff88801b6a9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801b6a9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
#1: ffffc9000ed2fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc9000ed2fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
#2: ffffffff8f34ac60 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffff888034aa7160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#3: ffff888034aa7160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff888034aa7160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555
#4: ffff88803bd94310 (&devlink->lock_key#7){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
#4: ffff88803bd94310 (&devlink->lock_key#7){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff88803bd94310 (&devlink->lock_key#7){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555
#5: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x113/0x780 drivers/net/netdevsim/netdev.c:1185
#6: ffff88803fb84f38 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2801 [inline]
#6: ffff88803fb84f38 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#6: ffff88803fb84f38 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1197/0x22b0 net/core/dev.c:12451
4 locks held by kworker/u8:15/3599:
#0: ffff88801b6ae938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801b6ae938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
#1: ffffc9000efefc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc9000efefc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
#2: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff88806426bbd8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
3 locks held by klogd/5154:
2 locks held by getty/5549:
#0: ffff8880383460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
5 locks held by syz-executor/5799:
2 locks held by udevd/5934:
4 locks held by syz.1.8/5954:
2 locks held by syz.1.8/5985:
#0: ffff888038e4c480 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88806426bfa8 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
#1: ffff88806426bfa8 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: open_last_lookups fs/namei.c:4608 [inline]
#1: ffff88806426bfa8 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4855
2 locks held by syz.4.32/6080:
#0: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888026b348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888026b348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
2 locks held by syz.2.160/6970:
#0: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888026b348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888026b348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
2 locks held by syz.0.184/7136:
#0: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888038e4c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888026b348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888026b348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
1 lock held by syz-executor/7285:
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
1 lock held by syz-executor/7384:
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
7 locks held by syz.8.221/7391:
6 locks held by syz-executor/7395:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xfaa/0x1000 kernel/hung_task.c:515
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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 2e 2d 93 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 1f c5 fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 da 74 fa 05 cc 44 89 f9 80 e1 07
RSP: 0000:ffffc900001679d0 EFLAGS: 00000202
RAX: 1ffffffff336d600 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff99b6b690 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853105c0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99b6b400 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126225000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c375ead CR3: 000000001127a000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1970
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
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