INFO: task syz.5.4002:26002 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4002 state:D stack:27496 pid:26002 tgid:26000 ppid:25564 task_flags:0x400140 flags:0x00080006
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592
___sys_sendmsg+0x134/0x1d0 net/socket.c:2646
__sys_sendmsg+0x16d/0x220 net/socket.c:2678
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f329338f7c9
RSP: 002b:00007f329427f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f32935e5fa0 RCX: 00007f329338f7c9
RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000004
RBP: 00007f3293413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32935e6038 R14: 00007f32935e5fa0 R15: 00007fffbadae508
INFO: task syz.8.4023:26135 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.4023 state:D stack:26120 pid:26135 tgid:26132 ppid:17920 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
___down_common kernel/locking/semaphore.c:268 [inline]
__down_common+0x31f/0x6e0 kernel/locking/semaphore.c:293
down+0x74/0xa0 kernel/locking/semaphore.c:100
console_lock+0x5b/0xa0 kernel/printk/printk.c:2843
class_console_lock_constructor include/linux/console.h:737 [inline]
set_selection_kernel+0x39/0x14d0 drivers/tty/vt/selection.c:379
set_selection_user+0xe8/0x140 drivers/tty/vt/selection.c:207
tioclinux+0x2b1/0x640 drivers/tty/vt/vt.c:3482
vt_ioctl+0x1fdf/0x30a0 drivers/tty/vt/vt_ioctl.c:753
tty_ioctl+0x661/0x1650 drivers/tty/tty_io.c:2792
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff212f8f7c9
RSP: 002b:00007ff2111f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff2131e6090 RCX: 00007ff212f8f7c9
RDX: 0000000000000000 RSI: 000000000000541c RDI: 0000000000000001
RBP: 00007ff213013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff2131e6128 R14: 00007ff2131e6090 R15: 00007fffcb47a068
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by kworker/u10:4/20660:
#0: ffff888145e84948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000502fc90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
2 locks held by kworker/u10:8/20667:
#0: ffff888145e84948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000503fc90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
2 locks held by kworker/u10:14/20777:
2 locks held by kworker/u10:18/21440:
#0: ffff888145e84948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc900050e7c90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
2 locks held by kworker/u10:20/21724:
#0: ffff888145e84948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000449fc90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
2 locks held by kworker/u10:30/22161:
#0: ffff888145e84948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000457fc90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
2 locks held by kworker/u10:33/24305:
#0: ffff888145e84948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000c477c90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
1 lock held by syz.0.3758/24703:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xad/0xe0 drivers/tty/tty_io.c:1691
2 locks held by syz.7.3881/25341:
#0: ffffffff901e8710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e8010a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
2 locks held by getty/25387:
#0: ffff88814d4090a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900044232f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
2 locks held by syz.5.4002/26002:
#0: ffffffff901e8710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e8010a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
6 locks held by syz.9.4018/26089:
1 lock held by syz.8.4023/26135:
#0: ffffffff8f07b448 (vc_sel.lock){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffffffff8f07b448 (vc_sel.lock){+.+.}-{4:4}, at: set_selection_kernel+0x34/0x14d0 drivers/tty/vt/selection.c:378
1 lock held by syz.0.4024/26158:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xad/0xe0 drivers/tty/tty_io.c:1691
2 locks held by syz.0.4035/26348:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
#1: ffff8880255731c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x37/0x500 drivers/tty/tty_io.c:1406
1 lock held by syz.3.4066/26686:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.3.4066/26693:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.6.4070/26716:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.2.4049/26770:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
2 locks held by syz.4.4086/26904:
#0: ffffffff901e8710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e8010a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
1 lock held by syz.1.4089/27030:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.7.4104/27249:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:798 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0x150/0x3c0 drivers/tty/pty.c:765
1 lock held by syz.9.4107/27278:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.5.4110/27326:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.8.4105/27384:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.8.4105/27387:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
2 locks held by syz-executor/27578:
#0: ffff8880689a80e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880689a80e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880689a80e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880689a80e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e8010a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz.0.4118/27650:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
4 locks held by syz.6.4125/27778:
#0: ffff8880723ed7b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1255
#1: ffff88805518d1c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182
#2: ffff88808c806088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#3: ffff888141eb75a8 (kn->active#164){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff888141eb75a8 (kn->active#164){.+.+}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
1 lock held by syz.3.4126/27784:
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f06ee88 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
3 locks held by syz.4.4130/27901:
3 locks held by syz-executor/27904:
2 locks held by syz-executor/27915:
#0: ffffffff908ac3a8 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:185 [inline]
#0: ffffffff908ac3a8 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:277 [inline]
#0: ffffffff908ac3a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574
#1: ffffffff90142268 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff90142268 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff90142268 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x5f6/0x1f50 net/core/rtnetlink.c:4071
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x133/0x180 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xe66/0x1180 kernel/hung_task.c:515
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246