INFO: task syz-executor:5826 blocked for more than 143 seconds.
Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22968 pid:5826 tgid:5826 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super fs/super.c:506 [inline]
deactivate_super+0xde/0x100 fs/super.c:502
cleanup_mnt+0x225/0x450 fs/namespace.c:1435
task_work_run+0x14d/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x230 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3cacd8fc97
RSP: 002b:00007ffebeab3318 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3cace1089d RCX: 00007f3cacd8fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffebeab33d0
RBP: 00007ffebeab33d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffebeab4460
R13: 00007f3cace1089d R14: 000000000010dbc0 R15: 00007ffebeab44a0
INFO: task syz.4.2393:17852 blocked for more than 143 seconds.
Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2393 state:D stack:28856 pid:17852 tgid:17851 ppid:10161 task_flags:0x400040 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
___down_common+0x2d8/0x460 kernel/locking/semaphore.c:229
__down_common kernel/locking/semaphore.c:250 [inline]
__down+0x20/0x30 kernel/locking/semaphore.c:258
down+0x74/0xa0 kernel/locking/semaphore.c:64
console_lock+0x5b/0xa0 kernel/printk/printk.c:2849
con_install+0x99/0x600 drivers/tty/vt/vt.c:3515
tty_driver_install_tty drivers/tty/tty_io.c:1304 [inline]
tty_init_dev.part.0+0x99/0x500 drivers/tty/tty_io.c:1416
tty_init_dev include/linux/err.h:70 [inline]
tty_open_by_driver drivers/tty/tty_io.c:2082 [inline]
tty_open+0xa50/0xf90 drivers/tty/tty_io.c:2129
chrdev_open+0x231/0x6a0 fs/char_dev.c:414
do_dentry_open+0x741/0x1c10 fs/open.c:956
vfs_open+0x82/0x3f0 fs/open.c:1086
do_open fs/namei.c:3880 [inline]
path_openat+0x1e5e/0x2d40 fs/namei.c:4039
do_filp_open+0x20b/0x470 fs/namei.c:4066
do_sys_openat2+0x11b/0x1d0 fs/open.c:1429
do_sys_open fs/open.c:1444 [inline]
__do_sys_openat fs/open.c:1460 [inline]
__se_sys_openat fs/open.c:1455 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1455
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5d9f98e969
RSP: 002b:00007f5da07c5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5d9fbb5fa0 RCX: 00007f5d9f98e969
RDX: 0000000000000102 RSI: 0000200000000800 RDI: ffffffffffffff9c
RBP: 00007f5d9fa10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5d9fbb5fa0 R15: 00007ffd2b030108
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
1 lock held by dhcpcd/5494:
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x1b4/0x320 net/ipv6/addrconf.c:4800
2 locks held by syz-executor/5826:
#0: ffff888060e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888060e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888060e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888060e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by kworker/u8:3/12663:
3 locks held by kworker/u8:25/13692:
#0: ffff88801b489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc900034c7d18 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
2 locks held by kworker/u8:32/13697:
2 locks held by getty/16756:
#0: ffff88814d0ac0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90004ea32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz.3.2315/17471:
#0: ffffffff901c8650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629
5 locks held by syz.6.2389/17837:
1 lock held by syz.5.2390/17834:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xad/0xe0 drivers/tty/tty_io.c:1700
2 locks held by syz.4.2393/17852:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
#1: ffff88807def71c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x37/0x500 drivers/tty/tty_io.c:1415
2 locks held by syz-executor/17903:
#0: ffff88805eb7e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88805eb7e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88805eb7e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88805eb7e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
1 lock held by syz.1.2423/18190:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:823 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xff/0x360 drivers/tty/pty.c:790
1 lock held by syz.9.2432/18276:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
2 locks held by syz-executor/18326:
#0: ffff888030d980e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888030d980e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888030d980e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888030d980e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
1 lock held by syz.7.2442/18441:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.3.2448/18588:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.0.2440/18583:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.0.2440/18586:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.5.2456/18788:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.5.2456/18789:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.6.2449/18913:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
1 lock held by syz.6.2449/18914:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
2 locks held by syz.6.2449/18921:
#0: ffffffff90110710 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:514
#1: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: fib_net_exit_batch+0x15/0x130 net/ipv4/fib_frontend.c:1675
2 locks held by syz-executor/18922:
#0: ffffffff8f4eff60 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#0: ffffffff8f4eff60 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#0: ffffffff8f4eff60 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574
#1: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064
1 lock held by syz.8.2453/18960:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
2 locks held by syz.4.2460/19000:
#0: ffffffff90110710 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:514
#1: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21d/0x7d0 net/ipv4/ip_tunnel.c:1160
4 locks held by syz.4.2460/19002:
1 lock held by syz.4.2460/19003:
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8f0a7928 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2129
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:437
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245