INFO: task syz.5.4279:8056 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4279 state:D stack:27608 pid:8056 tgid:8035 ppid:32420 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_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
genl_family_rcv_msg_doit+0x206/0x2f0 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:2552
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2630
___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
__sys_sendmsg+0x16d/0x220 net/socket.c:2716
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5afe38eec9
RSP: 002b:00007f5aff20f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5afe5e6270 RCX: 00007f5afe38eec9
RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000007
RBP: 00007f5afe411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5afe5e6308 R14: 00007f5afe5e6270 R15: 00007ffcdb688a68
Showing all locks held in the system:
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
6 locks held by kworker/u10:19/25843:
2 locks held by syz.5.4279/8056:
#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.3.4280/8042:
#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.0.4288/8154:
#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/8443:
#0: ffff88807ccfe0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807ccfe0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807ccfe0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88807ccfe0e0 (&type->s_umount_key#51){+.+.}-{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.9.4666/13440:
#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_version_set_doit+0xc4/0x7a0 fs/nfsd/nfsctl.c:1730
6 locks held by syz.8.4789/14964:
3 locks held by syz.7.4792/15040:
4 locks held by dhcpcd-run-hook/15046:
=============================================
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: 25843 Comm: kworker/u10:19 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: netns cleanup_net
RIP: 0010:stack_trace_consume_entry+0x8b/0x170 kernel/stacktrace.c:89
Code: 81 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 0c 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 98 00 00 00 8b 43 0c 85 c0 75 57 48 b8 00 00 00 00 00
RSP: 0018:ffffc9000426f358 EFLAGS: 00000202
RAX: 0000000000000007 RBX: ffffc9000426f438 RCX: ffffc9000426f2cc
RDX: 0000000000000000 RSI: ffffffff82616192 RDI: ffffc9000426f444
RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000005 R11: 000000000000a104 R12: ffffffff81a5f190
R13: ffffc9000426f438 R14: 0000000000000000 R15: ffff8880313c9e40
FS: 0000000000000000(0000) GS:ffff888124e6f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdf5c0db18 CR3: 000000007de4a000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x88/0x100 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:559
__call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3123
kernfs_put.part.0+0x162/0x640 fs/kernfs/dir.c:591
kernfs_put fs/kernfs/dir.c:1724 [inline]
kernfs_remove_by_name_ns+0xdf/0x110 fs/kernfs/dir.c:1718
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files+0x96/0x1c0 fs/sysfs/group.c:28
sysfs_remove_group+0x8b/0x180 fs/sysfs/group.c:322
sysfs_remove_groups fs/sysfs/group.c:346 [inline]
sysfs_remove_groups+0x60/0xa0 fs/sysfs/group.c:338
device_remove_groups drivers/base/core.c:2843 [inline]
device_remove_attrs+0x192/0x290 drivers/base/core.c:2973
device_del+0x38e/0x9f0 drivers/base/core.c:3877
unregister_netdevice_many_notify+0x14f0/0x24c0 net/core/dev.c:12289
ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
ops_undo_list+0x8fc/0xab0 net/core/net_namespace.c:248
cleanup_net+0x41b/0x8b0 net/core/net_namespace.c:695
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