INFO: task syz.2.947:15353 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.2.947 state:D stack:28184 pid:15353 tgid:15352 ppid:13232 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7048
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:411
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4669 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4828
do_file_open+0x203/0x440 fs/namei.c:4857
do_sys_openat2+0x105/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8c5378df90
RSP: 002b:00007f8c54683b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8c5378df90
RDX: 0000000000000002 RSI: 00007f8c54683c10 RDI: 00000000ffffff9c
RBP: 00007f8c54683c10 R08: 0000000000000000 R09: 00007f8c54683987
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f8c539e6038 R14: 00007f8c539e5fa0 R15: 00007ffdb9cea7d8
INFO: task syz.5.992:15748 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.5.992 state:D stack:27104 pid:15748 tgid:15725 ppid:14136 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7048
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:411
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4669 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4828
do_file_open+0x203/0x440 fs/namei.c:4857
do_sys_openat2+0x105/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f706af8df90
RSP: 002b:00007f706be11b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f706af8df90
RDX: 0000000000000002 RSI: 00007f706be11c10 RDI: 00000000ffffff9c
RBP: 00007f706be11c10 R08: 0000000000000000 R09: 00007f706be11986
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f706b1e6308 R14: 00007f706b1e6270 R15: 00007ffd8dcb8ff8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e144f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e144f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e144f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:7/1986:
#0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90004ee7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f51bfc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by kworker/u8:9/2985:
#0: ffff88801d2b3148 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000b95fc40 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffff88814476f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88814476f198 (&dev->mutex){....}-{4:4}, at: usb_remote_wakeup+0x23/0x130 drivers/usb/core/hub.c:3886
4 locks held by udevd/5194:
2 locks held by getty/5576:
#0: ffff88802efe60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/5832:
1 lock held by syz.8.830/12876:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xae/0xd0 drivers/tty/tty_io.c:1691
1 lock held by syz.6.864/13184:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xae/0xd0 drivers/tty/tty_io.c:1691
4 locks held by syz.3.866/13205:
1 lock held by syz.2.947/15353:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
1 lock held by syz.5.992/15748:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
1 lock held by syz.1.1001/15817:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
3 locks held by kworker/1:12/17347:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003617c40 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8e14a578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e14a578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:961
1 lock held by syz.4.1076/17448:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
1 lock held by syz.0.1077/17452:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
1 lock held by syz.0.1077/17453:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
1 lock held by syz.8.1114/18267:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120
1 lock held by syz.7.1203/19660:
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:254 [inline]
#0: ffffffff8e9827a8 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0x108/0x340 drivers/tty/pty.c:798
1 lock held by syz.1.1379/21605:
#0: ffffffff8e14a440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3828
1 lock held by syz.1.1379/21607:
1 lock held by syz.6.1382/21638:
1 lock held by syz.6.1382/21640:
2 locks held by syz.2.1383/21639:
#0: ffffffff8f51bfc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f51bfc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e14a578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e14a578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 3f 29 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07dc0 EFLAGS: 000002c2
RAX: 0000000000414005 RBX: ffffffff81977eae RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d9a99b4 RDI: ffffffff8be09d60
RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb
R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa2d8f0
R13: 1ffffffff1bd29d0 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125bf7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3b6698 CR3: 000000002fed0000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:758
start_kernel+0x38b/0x3e0 init/main.c:1209
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147