INFO: task syz.4.3141:18079 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3141 state:D
stack:25256 pid:18079 tgid:18076 ppid:16479 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1494
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x702/0xe10 net/netlink/af_netlink.c:2331
__netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2446
genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075
genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline]
genl_rcv_msg+0x5e8/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f934799ce59
RSP: 002b:00007f934891d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9347c15fa0 RCX: 00007f934799ce59
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007f9347a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9347c16038 R14: 00007f9347c15fa0 R15: 00007ffc158bb048
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5386:
#0: ffff8880371af0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by syz.2.2758/16339:
#0: ffffffff8fe392e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8b1c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
3 locks held by syz.4.3141/18079:
#0: ffffffff8fe392e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff88805beef6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2410
#2:
ffffffff8ec8b1c0
(
nfsd_mutex
){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1494
3 locks held by kworker/u8:25/19821:
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000513fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000513fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8fdc8e80 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by syz.0.3953/21426:
#0:
ffffffff8fe392e8
(
cb_lock
){++++}-{4:4}
, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1:
ffffffff8ec8b1c0
(
nfsd_mutex
){+.+.}-{4:4}
, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
8 locks held by syz.3.4315/22996:
2 locks held by syz.7.4319/23018:
#0:
ffffffff8fdc8e80
(
rtnl_mutex
){+.+.}-{4:4}
, at: tun_detach drivers/net/tun.c:641 [inline]
, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3505
#1:
ffffffff8e962fa8
(
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by syz.1.4324/23043:
#0:
ffffffff903237a8
(
&ops->srcu#2
){.+.+}-{0:0}
, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1:
ffffffff8fdc8e80
(
rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4150
2 locks held by syz.5.4325/23046:
#0: ffffffff90327be0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff90327be0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff90327be0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8fdc8e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8fdc8e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8fdc8e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4150
1 lock held by syz.5.4325/23047:
#0:
ffffffff8fdc8e80
(
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7068
1 lock held by syz.5.4325/23048:
#0: ffffffff8fdc8e80 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7068
1 lock held by syz.5.4325/23049:
#0:
ffffffff8fdc8e80
(
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7068
=============================================
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 04/18/2026
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:162 [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:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 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: 22996 Comm: syz.3.4315 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:touch_softlockup_watchdog+0x15/0x30 kernel/watchdog.c:712
Code: 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 27 ba ff ff 65 48 c7 05 83 e3 73 11 ff ff ff ff <65> 8b 3d a8 53 73 11 e9 8f 45 c8 ff 66 66 66 66 66 66 2e 0f 1f 84
RSP: 0018:ffffc90005836a10 EFLAGS: 00000093
RAX: ffffffff81c5fc79 RBX: dffffc0000000000 RCX: ffff88809d7cbe00
RDX: 0000000000000000 RSI: ffffffff8c28b7c0 RDI: 00000000ffffffff
RBP: ffffffff9a7a1d50 R08: ffff888026720237 R09: 1ffff11004ce4046
R10: dffffc0000000000 R11: ffffffff8ba7a690 R12: 1ffffffff34f43aa
R13: 00000000ffffffff R14: dffffc0000000000 R15: 00000000000007ff
FS: 00007fabf60b46c0(0000) GS:ffff88812528b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555574e8e4e8 CR3: 000000007957e000 CR4: 00000000003526f0
Call Trace:
touch_nmi_watchdog include/linux/nmi.h:151 [inline]
wait_for_lsr+0x16a/0x2f0 drivers/tty/serial/8250/8250_port.c:1977
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
ip_vs_schedule+0x15e9/0x1d70 net/netfilter/ipvs/ip_vs_core.c:696
udp_conn_schedule+0x391/0x7a0 net/netfilter/ipvs/ip_vs_proto_udp.c:78
ip_vs_try_to_schedule net/netfilter/ipvs/ip_vs_core.c:1657 [inline]
ip_vs_in_hook+0xc50/0x1bf0 net/netfilter/ipvs/ip_vs_core.c:2229
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook+0x22a/0x3a0 include/linux/netfilter.h:273
__ip_local_out+0x558/0x6a0 net/ipv4/ip_output.c:120
ip_local_out+0x2a/0x190 net/ipv4/ip_output.c:129
__ip_queue_xmit+0x116a/0x1bb0 net/ipv4/ip_output.c:534
l2tp_xmit_queue net/l2tp/l2tp_core.c:1220 [inline]
l2tp_xmit_core net/l2tp/l2tp_core.c:1317 [inline]
l2tp_xmit_skb+0x102c/0x17e0 net/l2tp/l2tp_core.c:1333
pppol2tp_sendmsg+0x40a/0x5f0 net/l2tp/l2tp_ppp.c:303
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmmsg+0x27c/0x4e0 net/socket.c:2841
__do_sys_sendmmsg net/socket.c:2868 [inline]
__se_sys_sendmmsg net/socket.c:2865 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2865
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fabf519ce59
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:00007fabf60b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fabf5415fa0 RCX: 00007fabf519ce59
RDX: 0000000000034000 RSI: 0000200000004380 RDI: 0000000000000004
RBP: 00007fabf5232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fabf5416038 R14: 00007fabf5415fa0 R15: 00007ffeb91525f8