INFO: task syz-executor:5613 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-executor state:D stack:21096 pid:5613 tgid:5613 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5581 [inline]
__schedule+0x1b47/0x5b40 kernel/sched/core.c:7384
__schedule_loop kernel/sched/core.c:7461 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7476
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7533
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1379
deactivate_locked_super+0xbe/0x110 fs/super.c:586
cleanup_mnt+0x3d3/0x460 fs/namespace.c:1329
task_work_run+0x1d9/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf09d9f397
RSP: 002b:00007fffbc6d27d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fcf09e344bb RCX: 00007fcf09d9f397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffbc6d2890
RBP: 00007fffbc6d2890 R08: 00007fffbc6d3890 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffbc6d3920
R13: 00007fcf09e344bb R14: 0000000000033ad3 R15: 00007fffbc6d3960
Showing all locks held in the system:
locks held by khungtaskd/34: 1, last CPU#1:
#0: ffffffff8f15a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8f15a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8f15a3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/1:2/1229: 3, last CPU#1:
#0: ffff888020ada148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888020ada148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888020ada148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff888020ada148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000565fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000565fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000565fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000565fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff888029d4e1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff888029d4e1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917
locks held by getty/5367: 2, on CPU#1:
#0: ffff8880346c30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5613: 2, on CPU#0:
#0: ffff888035c8e0e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888035c8e0e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888035c8e0e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f49de60 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz-executor/5614: 2, on CPU#0:
#0: ffff8880770780e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880770780e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff8880770780e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f49de60 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz-executor/6337: 2, on CPU#0:
#0: ffff88807f9f80e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807f9f80e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807f9f80e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f49de60 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz.2.312/6974: 3, on CPU#0:
#0: ffff88807ca18ef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1408
#1: ffff8880297f6460 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff8880297f6460 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f49de60 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874
locks held by syz-executor/7217: 2, on CPU#0:
#0: ffff88807f0640e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807f0640e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807f0640e8 (&type->s_umount_key#78){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f49de60 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz-executor/8959: 1, last CPU#0:
#0: ffff88803369e460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:505
locks held by syz.6.876/9077: 2, last CPU#0:
#0: ffffffff8f15a3a0 (rcu_read_lock){....}-{1:3}, at: __debug_check_no_obj_freed lib/debugobjects.c:1160 [inline]
#0: ffffffff8f15a3a0 (rcu_read_lock){....}-{1:3}, at: debug_check_no_obj_freed+0xcb/0x450 lib/debugobjects.c:1201
#1: ffff888029c13fa8 (&lruvec->lru_lock){..-.}-{3:3}, at: folio_lruvec_lock_irqsave+0x278/0x560 mm/memcontrol.c:1544
locks held by kworker/u8:26/9185: 6, last CPU#1:
#0: ffff88801c286148 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801c286148 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801c286148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88801c286148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90008957c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90008957c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90008957c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90008957c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffffffff9066c5a8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
#3: ffff888029125128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff888029125128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff888029125128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:575
#4: ffff888029124258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:308 [inline]
#4: ffff888029124258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff888029124258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:575
#5: ffffffff9067ae20 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1201
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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+0x1058/0x10d0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4967 Comm: klogd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:181 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x49/0x80 kernel/kcov.c:213
Code: 29 89 d6 81 e6 00 01 00 0f 81 fe 00 01 00 00 40 0f 95 c6 81 fa 00 00 00 10 0f 93 c2 40 08 f2 75 35 83 b9 44 17 00 00 00 74 2c <8b> 91 18 17 00 00 83 fa 02 75 21 48 8b 91 20 17 00 00 48 8b 32 48
RSP: 0018:ffffc90002e976b8 EFLAGS: 00000246
RAX: ffffffff8bfb5086 RBX: 00000000fffffffe RCX: ffff88807fb21f40
RDX: 8000000000000000 RSI: 00000000fffffffe RDI: 00000000ffffffff
RBP: ffffc90002e977d8 R08: ffffc90002e97757 R09: 0000000000000000
R10: ffffc90002e97740 R11: fffff520005d2eeb R12: 0000000000000003
R13: dffffc0000000000 R14: ffffc90002e97ac6 R15: 0000000000000003
FS: 00007fc1eca7cc80(0000) GS:ffff88812462e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faea1fed158 CR3: 000000007f4ee000 CR4: 00000000003526f0
Call Trace:
number+0x886/0xed0 lib/vsprintf.c:551
vsnprintf+0x91b/0xef0 lib/vsprintf.c:2910
sprintf+0xe7/0x140 lib/vsprintf.c:3113
print_time kernel/printk/printk.c:1359 [inline]
info_print_prefix+0x16b/0x360 kernel/printk/printk.c:1385
record_print_text+0x181/0x4b0 kernel/printk/printk.c:1434
syslog_print+0x3ab/0x610 kernel/printk/printk.c:1645
do_syslog+0x583/0x7d0 kernel/printk/printk.c:1763
__do_sys_syslog kernel/printk/printk.c:1855 [inline]
__se_sys_syslog kernel/printk/printk.c:1853 [inline]
__x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1853
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc1ecc46a37
Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007fff913993d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000067
RAX: ffffffffffffffda RBX: 00007fc1ecde6490 RCX: 00007fc1ecc46a37
RDX: 00000000000003ff RSI: 00007fc1ecde6490 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000206 R12: 00007fc1ecde6490
R13: 00007fc1ecdc3dfe R14: 00007fc1ecde67f4 R15: 00007fc1ecde67f4