INFO: task syz.5.13104:21831 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.13104 state:D stack:26248 pid:21831 tgid:21828 ppid:17513 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1484
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1027
netlink_dump+0x722/0xe80 net/netlink/af_netlink.c:2325
__netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440
genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1076
genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline]
genl_rcv_msg+0x5e8/0x7a0 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ef639c629
RSP: 002b:00007f8ef716e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8ef6615fa0 RCX: 00007f8ef639c629
RDX: 0000000000000800 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007f8ef6432b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ef6616038 R14: 00007f8ef6615fa0 R15: 00007ffdadc307a8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5586:
#0: ffff888036fc20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:23/4893:
1 lock held by udevd/14362:
#0: ffff88802648c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by udevd/14671:
#0: ffff888026656358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by udevd/14749:
#0: ffff888025f2a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
2 locks held by syz.2.12484/19508:
#0: ffffffff8fc39470 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea86928 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1893
3 locks held by syz-executor/20221:
3 locks held by syz.5.13104/21831:
#0: ffffffff8fc39470 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffff8880788046f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#2: ffffffff8ea86928 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1484
2 locks held by syz.7.15075/28641:
#0: ffffffff8fbbcff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577
#1: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 28641 Comm: syz.7.15075 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:lock_acquire+0xde/0x2e0 kernel/locking/lockdep.c:5868
Code: e8 c7 b1 0b 0a 65 ff 05 b0 69 7a 11 45 31 c9 f7 c3 00 02 00 00 41 0f 94 c1 4c 89 ef 8b 74 24 04 89 ea 44 89 e1 45 89 f8 6a 00 <6a> 00 6a 00 ff b4 24 88 00 00 00 41 56 e8 80 02 00 00 48 83 c4 28
RSP: 0018:ffffc9000dc3f808 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000046 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880791e6198
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff2022e57 R12: 0000000000000000
R13: ffff8880791e6198 R14: 0000000000000000 R15: 0000000000000001
FS: 00007fabc4bfd6c0(0000) GS:ffff888125566000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcc233e82f8 CR3: 00000000864dc000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
skb_dequeue+0x2d/0x160 net/core/skbuff.c:3970
wireless_nlevent_flush net/wireless/wext-core.c:353 [inline]
wext_netdev_notifier_call+0x69/0x110 net/wireless/wext-core.c:371
notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
call_netdevice_notifiers net/core/dev.c:2301 [inline]
unregister_netdevice_many_notify+0x1cbf/0x2370 net/core/dev.c:12421
ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248
setup_net+0x2f0/0x340 net/core/net_namespace.c:462
copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581
create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226
ksys_unshare+0x4f4/0x900 kernel/fork.c:3174
__do_sys_unshare kernel/fork.c:3245 [inline]
__se_sys_unshare kernel/fork.c:3243 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3243
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fabc3d9c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fabc4bfd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fabc4016090 RCX: 00007fabc3d9c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007fabc3e32b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fabc4016128 R14: 00007fabc4016090 R15: 00007ffd6acfda38