INFO: task syz.6.5837:29498 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.5837 state:D stack:27008 pid:29498 tgid:29494 ppid:26434 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
nfsd_nl_svc_export_get_reqs_dumpit+0xf7/0xc40 fs/nfsd/export.c:674
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2350
__netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2465
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+0x5e1/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
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: 0033:0x7f277539e159
RSP: 002b:00007f27761db028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2775625fa0 RCX: 00007f277539e159
RDX: 0000000004044810 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007f277543506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2775626038 R14: 00007f2775625fa0 R15: 00007ffff53ab148
Showing all locks held in the system:
locks held by ksoftirqd/1/24: 1, last CPU#1:
#0: ffff8880593f6c98 (&p->tcfa_lock){+.-.}-{3:3}, at: class_raw_spinlock_constructor include/linux/spinlock.h:559 [inline]
#0: ffff8880593f6c98 (&p->tcfa_lock){+.-.}-{3:3}, at: __hrtimer_rearm_deferred+0x99/0x4b0 kernel/time/hrtimer.c:2188
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5373: 2, on CPU#0:
#0: ffff8880364730a0 (&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 syz.2.4955/25955: 2, on CPU#0:
#0: ffffffff902c5cc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057
locks held by syz.6.5837/29498: 3, on CPU#1:
#0: ffffffff902c5cc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff88802b3a36e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2429
#2: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_get_reqs_dumpit+0xf7/0xc40 fs/nfsd/export.c:674
=============================================
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 09/16/2026
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: 24 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:37 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:179 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:242 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x10/0xb0 kernel/kcov.c:310
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d f8 7e cd 11 <65> 48 8b 15 f8 7e cd 11 f7 c2 00 01 00 ff 74 2c 41 89 d0 41 81 e0
RSP: 0018:ffffc900001e7a80 EFLAGS: 00000046
RAX: ffffffff81b49852 RBX: 0000000000000000 RCX: ffff88801e6fddc0
RDX: 8000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001e7b70 R08: 0000000000000100 R09: 0000000000000002
R10: 0000000000000003 R11: 8000000000000100 R12: 1ffff9200003cf5c
R13: dffffc0000000000 R14: 0000000000000000 R15: 000000d54f643000
FS: 0000000000000000(0000) GS:ffff888124dca000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565270055f18 CR3: 000000000eb48000 CR4: 00000000003526f0
Call Trace:
ktime_get+0x22/0x220 kernel/time/timekeeping.c:999
clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363
hrtimer_rearm kernel/time/hrtimer.c:2176 [inline]
__hrtimer_rearm_deferred+0x36c/0x4b0 kernel/time/hrtimer.c:2196
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 4d c1 ba f5 f7 c3 00 02 00 00 74 05 e8 f0 0b e7 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 ce ab f5 65 48 8b 05 ec 40 ac 07 48 85 c0 74 18 5b 41 5e c3
RSP: 0018:ffffc900001e7cc8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000283 RCX: 8000000000000101
RDX: 0000000000000000 RSI: ffffffff8e41595b RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff907a5f7f R09: 1ffffffff20f4bef
R10: dffffc0000000000 R11: fffffbfff20f4bf0 R12: 0000000000000009
R13: 0000000000000008 R14: ffff8880b8728280 R15: 0000000000000100
handle_softirqs+0x226/0x860 kernel/softirq.c:645
run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099
smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
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