INFO: task syz.4.538:8232 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.538 state:D stack:27240 pid:8232 tgid:8230 ppid:7856 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_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880
genl_family_rcv_msg_doit+0x209/0x2f0 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+0x5aa/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+0xa98/0xc70 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/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f054db8f749
RSP: 002b:00007f054ea01038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f054dde5fa0 RCX: 00007f054db8f749
RDX: 0000000000000000 RSI: 0000200000003140 RDI: 0000000000000003
RBP: 00007f054dc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f054dde6038 R14: 00007f054dde5fa0 R15: 00007fffe23e2b48
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/0:4/5917:
#0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffff8880b8424088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline]
#1: ffff8880b8424088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6923
#2: ffffffff8eecbaf8 (pool_lock#2){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
#2: ffffffff8eecbaf8 (pool_lock#2){-.-.}-{2:2}, at: free_obj_work+0x1be/0x3d0 lib/debugobjects.c:498
2 locks held by syz.0.411/7656:
#0: ffffffff9018f210 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880
2 locks held by syz.4.538/8232:
#0: ffffffff9018f210 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880
2 locks held by syz-executor/8406:
#0: ffff8880529460e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880529460e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880529460e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880529460e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz.2.747/9222:
#0: ffffffff9018f210 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x18a/0x800 fs/nfsd/nfsctl.c:1805
2 locks held by getty/10123:
#0: ffff88814de780a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000b57d2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz.1.989/10294:
#0: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.3.991/10303:
#0: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.6.993/10307:
#0: ffffffff8f71fae8 (mon_lock){+.+.}-{4:4}, at: mon_text_release+0x4e/0x3d0 drivers/usb/mon/mon_text.c:650
#1: ffffffff8e3cfa40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3820
1 lock held by syz.7.995/10318:
=============================================
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 10/25/2025
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+0x675/0x7d0 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 67 6f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 74 2c 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 00000000002e54b5 RBX: 0000000000000000 RCX: ffffffff8b5db2a9
RDX: 0000000000000000 RSI: ffffffff8da29329 RDI: ffffffff8bf078c0
RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e097a00 R14: ffffffff90824cd0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b318caff8 CR3: 000000003451c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x38d/0x500 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3f6/0x4e0 init/main.c:1111
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148