INFO: task syz-executor:16360 blocked for more than 142 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24152 pid:16360 tgid:16360 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1347
deactivate_locked_super+0xc1/0x1a0 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:1327
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+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x419/0x4b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f65467901f7
RSP: 002b:00007ffe2feec7f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f6546811d7d RCX: 00007f65467901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe2feec8b0
RBP: 00007ffe2feec8b0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe2feed940
R13: 00007f6546811d7d R14: 00000000000c3b9e R15: 00007ffe2feed980
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
1 lock held by khungtaskd/31:
#0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/15937:
#0: ffff88803b0e00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803b0e00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803b0e00e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88803b0e00e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/16360:
#0: ffff888030b8c0e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888030b8c0e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888030b8c0e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888030b8c0e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz.1.2456/16691:
#0: ffffffff8ff8c250 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
2 locks held by syz-executor/16949:
#0: ffff8880295800e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880295800e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880295800e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880295800e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
3 locks held by kworker/u10:3/17130:
#0: ffff88801b069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000d877d10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff8fee8908 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
2 locks held by syz-executor/17938:
#0: ffff88802ed940e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802ed940e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802ed940e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88802ed940e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/18520:
#0: ffff888031cf80e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888031cf80e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888031cf80e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888031cf80e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/18567:
#0: ffff8880762a60e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880762a60e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880762a60e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880762a60e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/18621:
#0: ffff88805a04a0e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805a04a0e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805a04a0e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88805a04a0e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/18896:
#0: ffff88802faa00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802faa00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802faa00e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88802faa00e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/19022:
#0: ffff88807d3f40e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807d3f40e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807d3f40e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88807d3f40e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/19176:
#0: ffff88807a0500e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807a0500e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807a0500e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88807a0500e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/19193:
#0: ffff888031b580e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888031b580e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888031b580e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888031b580e0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
4 locks held by syz-executor/19329:
11 locks held by syz-executor/19652:
1 lock held by syz.5.3064/19731:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 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: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_power_efficient gc_worker
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:246
Code: 96 09 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 a7 83 c0 11 <65> 8b 05 b8 83 c0 11 a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00
RSP: 0018:ffffc900000e7b50 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000040000 RCX: ffffffff8979f202
RDX: ffff88801da88000 RSI: 000000000002f728 RDI: 0000000000000004
RBP: ffffffff9ad173ac R08: 0000000000000004 R09: 000000000002f728
R10: 0000000000040000 R11: 0000000000000000 R12: ffff888024000000
R13: 000000000002f728 R14: dffffc0000000000 R15: 0000000000001770
FS: 0000000000000000(0000) GS:ffff888124e6f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feea869bd58 CR3: 0000000078bfe000 CR4: 00000000003526f0
Call Trace:
gc_worker+0x342/0x16e0 net/netfilter/nf_conntrack_core.c:1549
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245