INFO: task syz.2.7461:5900 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.7461 state:D stack:24104 pid:5900 tgid:5899 ppid:988 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7276
__schedule_loop kernel/sched/core.c:7353 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7368
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7425
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
nfsd_nl_unlock_export_doit+0x2ef/0x580 fs/nfsd/nfsctl.c:2724
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 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+0x7bd/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2713
___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
__sys_sendmsg net/socket.c:2799 [inline]
__do_sys_sendmsg net/socket.c:2804 [inline]
__se_sys_sendmsg net/socket.c:2802 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
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: 0033:0x7f569c59e159
RSP: 002b:00007f569d38f028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f569c825fa0 RCX: 00007f569c59e159
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007f569c63503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f569c826038 R14: 00007f569c825fa0 R15: 00007ffedc6482e8
Showing all locks held in the system:
locks held by ksoftirqd/1/24: 0, last CPU#1
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5371: 2, on CPU#0:
#0: ffff888032c3e0a0 (&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 kworker/u8:31/19424: 3, on CPU#0:
#0: ffff888032a31140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888032a31140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888032a31140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888032a31140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90005d8fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90005d8fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90005d8fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90005d8fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#2: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4230
locks held by syz.8.6929/3412: 2, on CPU#0:
#0: ffffffff902c3628 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057
locks held by syz-executor/3846: 1, last CPU#0:
#0: ffff888046eaa9b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
locks held by syz.2.7461/5900: 2, on CPU#0:
#0: ffffffff902c3628 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_unlock_export_doit+0x2ef/0x580 fs/nfsd/nfsctl.c:2724
locks held by kworker/1:1/6226: 5, last CPU#1:
#0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90004217c40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004217c40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004217c40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90004217c40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff902d2860 (nf_conntrack_mutex){+.+.}-{4:4}, at: nf_ct_iterate_cleanup+0x3f/0x500 net/netfilter/nf_conntrack_core.c:2365
#3: ffff8880b8728298 (hrtimer_bases.lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:595 [inline]
#3: ffff8880b8728298 (hrtimer_bases.lock){-.-.}-{2:2}, at: try_to_wake_up+0x67/0x14d0 kernel/sched/core.c:4308
#4: ffffffff9aa26748 (&____s->seqcount#2){----}-{0:0}, at: ktime_get+0x45/0x220 kernel/time/timekeeping.c:1002
locks held by syz.1.8097/8961: 2, on CPU#1:
#0: ffffffff902c3628 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_expkey_set_reqs_doit+0xfe/0xaf0 fs/nfsd/export.c:561
locks held by syz-executor/9384: 1, last CPU#0:
#0: ffffffff8f4f0f78 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
#0: ffffffff8f4f0f78 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline]
#0: ffffffff8f4f0f78 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline]
#0: ffffffff8f4f0f78 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_perm+0x251/0x560 security/tomoyo/file.c:826
locks held by syz.7.8518/10780: 2, last CPU#1:
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810 net/core/rtnetlink.c:3691
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0xb8/0x5d0 net/ipv6/ip6_fib.c:2319
locks held by syz.7.8518/10783: 1, on CPU#0:
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810 net/core/rtnetlink.c:3691
locks held by syz.0.8520/10799: 1, on CPU#0:
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_add_ifaddr+0x14d/0x3e0 net/ipv6/addrconf.c:3180
locks held by syz.9.8521/10803: 1, on CPU#0:
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7143
locks held by syz.9.8521/10804: 2, on CPU#0:
#0: ffffffff907a6a40 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff907a6a40 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff907a6a40 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595
#1: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#1: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by syz.9.8521/10805: 2, on CPU#0:
#0: ffffffff907a76b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff907a76b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff907a76b0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595
#1: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#1: ffffffff90252700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10780 Comm: syz.7.8518 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:native_apic_msr_write+0x18/0x50 arch/x86/include/asm/apic.h:204
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 81 ff cf 00 00 00 7f 0c 83 ff 20 74 2a 83 ff 30 74 25 eb 10 <81> ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00
RSP: 0018:ffffc90000a18d30 EFLAGS: 00000016
RAX: 1ffff110170e4791 RBX: ffff8880b8723c80 RCX: 0000000000000020
RDX: 8000000000000100 RSI: 0000000000012ef7 RDI: 0000000000000380
RBP: ffffc90000a18df0 R08: 0000000000000100 R09: 0000000000000001
R10: 0000000000000003 R11: ffffffff81754510 R12: 0000000000012ef7
R13: dffffc0000000000 R14: 0000000010004eda R15: 0000000000000020
FS: 00007f3c8d1116c0(0000) GS:ffff888124dd2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9dea5556c8 CR3: 000000004381a000 CR4: 00000000003526f0
Call Trace:
apic_write arch/x86/include/asm/apic.h:405 [inline]
lapic_next_event+0x11/0x20 arch/x86/kernel/apic/apic.c:418
clockevents_program_event+0x385/0x630 kernel/time/clockevents.c:372
hrtimer_rearm kernel/time/hrtimer.c:2169 [inline]
__hrtimer_rearm_deferred+0x36c/0x4b0 kernel/time/hrtimer.c:2189
hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:58 [inline]
hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:67 [inline]
irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
irqentry_exit+0x8d3/0x910 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:221
Code: f7 e8 8d 33 bc f5 f7 c3 00 02 00 00 74 05 e8 50 77 e8 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 94 42 ad f5 65 48 8b 05 0c 41 ad 07 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000a18f40 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000283 RCX: 8000000000000102
RDX: 0000000000000002 RSI: ffffffff8e475fde RDI: 0000000000000001
RBP: 0000000000000003 R08: ffffffff907a327f R09: 1ffffffff20f464f
R10: dffffc0000000000 R11: fffffbfff20f4650 R12: 0000000000000009
R13: 0000000000000008 R14: ffff8880b8728280 R15: 0000000000000100
handle_softirqs+0x226/0x860 kernel/softirq.c:645
do_softirq+0x77/0xd0 kernel/softirq.c:546
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
spin_unlock_bh include/linux/spinlock.h:407 [inline]
addrconf_ifdown+0x68a/0x1a30 net/ipv6/addrconf.c:3943
addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
call_netdevice_notifiers net/core/dev.c:2327 [inline]
unregister_netdevice_many_notify+0x17f9/0x2140 net/core/dev.c:12518
rtnl_delete_link net/core/rtnetlink.c:3657 [inline]
rtnl_dellink+0x5be/0x810 net/core/rtnetlink.c:3699
rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7137
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2713
___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
__sys_sendmsg net/socket.c:2799 [inline]
__do_sys_sendmsg net/socket.c:2804 [inline]
__se_sys_sendmsg net/socket.c:2802 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
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: 0033:0x7f3c8c19e159
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:00007f3c8d111028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3c8c425fa0 RCX: 00007f3c8c19e159
RDX: 0000000004000804 RSI: 0000200000000200 RDI: 0000000000000007
RBP: 00007f3c8c23503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3c8c426038 R14: 00007f3c8c425fa0 R15: 00007ffcb7a0b068