INFO: task syz.3.680:8741 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.680 state:D stack:25736 pid:8741 tgid:8740 ppid:5630 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_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1919
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:2572
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916
sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
__sock_sendmsg net/socket.c:818 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2715
___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
__sys_sendmsg net/socket.c:2801 [inline]
__do_sys_sendmsg net/socket.c:2806 [inline]
__se_sys_sendmsg net/socket.c:2804 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
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: 0033:0x7f7c67d9e159
RSP: 002b:00007f7c68c65028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7c68025fa0 RCX: 00007f7c67d9e159
RDX: 0000000000000004 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f7c67e3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c68026038 R14: 00007f7c68025fa0 R15: 00007fff9bd18798
INFO: task syz.1.692:8802 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.692 state:D stack:25736 pid:8802 tgid:8800 ppid:5617 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_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1919
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:2572
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916
sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
__sock_sendmsg net/socket.c:818 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2715
___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
__sys_sendmsg net/socket.c:2801 [inline]
__do_sys_sendmsg net/socket.c:2806 [inline]
__se_sys_sendmsg net/socket.c:2804 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
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: 0033:0x7f7c2df9e159
RSP: 002b:00007f7c2ee7b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7c2e225fa0 RCX: 00007f7c2df9e159
RDX: 0000000000000004 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f7c2e03506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c2e226038 R14: 00007f7c2e225fa0 R15: 00007ffc70f6da88
Showing all locks held in the system:
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: ffff8880366f40a0 (&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/1:13/6081: 3, 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: ffffc90006cdfc40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90006cdfc40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90006cdfc40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90006cdfc40 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff902d5020 (nf_conntrack_mutex){+.+.}-{4:4}, at: nf_ct_iterate_cleanup+0x3f/0x500 net/netfilter/nf_conntrack_core.c:2364
locks held by syz.2.651/8621: 2, on CPU#1:
#0: ffffffff902c5ca8 (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-executor/8731: 4, last CPU#1:
#0: ffffffff8ee36730 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff8ee36730 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10f/0x480 kernel/fork.c:1595
#1: ffff88807a0736b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#1: ffff88807a0736b8 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
#2: ffff8880320bd038 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
#2: ffff8880320bd038 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
#3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz.3.680/8741: 2, on CPU#1:
#0: ffffffff902c5ca8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1919
locks held by syz.1.692/8802: 2, on CPU#1:
#0: ffffffff902c5ca8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1919
locks held by syz.7.1004/10296: 2, on CPU#0:
#0: ffffffff902c5ca8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1919
locks held by syz.8.1760/13607: 2, last CPU#1:
#0: ffffffff90254960 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
#0: ffffffff90254960 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3587
#1: ffff88802a920018 (&xa->xa_lock#22){+.+.}-{3:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffff88802a920018 (&xa->xa_lock#22){+.+.}-{3:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffff88802a920018 (&xa->xa_lock#22){+.+.}-{3:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffff88802a920018 (&xa->xa_lock#22){+.+.}-{3:3}, at: __is_module_percpu_address+0x28/0x3f0 kernel/module/main.c:503
locks held by rm/13618: 1, last CPU#0:
#0: ffff8880320b9d38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff8880320b9d38 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
=============================================
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: 13607 Comm: syz.8.1760 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:_find_next_bit+0x81/0xe0 lib/find_bit.c:157
Code: 48 89 ef 48 bd 00 00 00 00 00 fc ff df 4d 23 3c 24 74 26 49 83 e6 c0 4d 89 f5 f3 49 0f bc c7 4c 01 e8 48 39 d8 48 0f 43 c3 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 c1 20 0c 07 cc 4e 8d 34 ef 49 83 c6
RSP: 0018:ffffc900043778f0 EFLAGS: 00000087
RAX: 0000000000005bc0 RBX: ffff8880829b6268 RCX: 0000000000005bc0
RDX: 0000000000005bc0 RSI: 0000000000100000 RDI: ffffffff971ce9f0
RBP: dffffc0000000000 R08: ffffffff81b0d2c8 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff204a921 R12: ffffffff971cf568
R13: 0000000000005bc0 R14: 0000000000005bc0 R15: ffffffffffffffff
FS: 00005555772d3500(0000) GS:ffff888124dc5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33e23ffc CR3: 000000007ee46000 CR4: 00000000003526f0
Call Trace:
find_next_bit include/linux/find.h:71 [inline]
zap_class+0x1e2/0x330 kernel/locking/lockdep.c:6351
__lockdep_free_key_range kernel/locking/lockdep.c:6503 [inline]
lockdep_unregister_key+0x1c3/0x350 kernel/locking/lockdep.c:6705
qdisc_lock_uninit include/net/pkt_sched.h:333 [inline]
__qdisc_destroy+0x1ab/0x470 net/sched/sch_generic.c:1124
qdisc_put net/sched/sch_generic.c:1150 [inline]
dev_shutdown+0x352/0x450 net/sched/sch_generic.c:1515
unregister_netdevice_many_notify+0x11f4/0x2140 net/core/dev.c:12553
unregister_netdevice_many net/core/dev.c:12637 [inline]
unregister_netdevice_queue+0x2f5/0x340 net/core/dev.c:12438
unregister_netdevice include/linux/netdevice.h:3485 [inline]
__tun_detach+0x1074/0x1900 drivers/net/tun.c:637
tun_detach drivers/net/tun.c:653 [inline]
tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3587
__fput+0x418/0xa50 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff63fb9e159
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:00007ffd17389de8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffd17389ed0 RCX: 00007ff63fb9e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000005d338 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b33620000 R11: 0000000000000246 R12: 00007ffd17389f10
R13: 00007ff63fe25fac R14: 000000000005d3e3 R15: 00007ff63fe25fa0