INFO: task syz.3.1200:10003 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1200 state:D stack:25512 pid:10003 tgid:10000 ppid:5616 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
nfsd_nl_expkey_get_reqs_dumpit+0xfd/0xd40 fs/nfsd/export.c:347
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331
__netlink_dump_start+0x589/0x7b0 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+0x5e1/0x7a0 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+0x7bb/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:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
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: 0033:0x7fd64c79de99
RSP: 002b:00007fd64d706028 EFLAGS: 00000246
ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd64ca26180 RCX: 00007fd64c79de99
RDX: 0000000004044810 RSI: 0000200000000180 RDI: 0000000000000005
RBP: 00007fd64c833eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd64ca26218 R14: 00007fd64ca26180 R15: 00007ffd6dbaead8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5370:
#0: ffff888032a3e0a0 (&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
3 locks held by kworker/1:11/7462:
#0: ffff88801b027140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801b027140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9001c06fc40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9001c06fc40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
2 locks held by syz.1.928/9102:
#0: ffffffff9009cba8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1:
ffffffff8ee8e620
(
nfsd_mutex
){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964
3 locks held by syz.3.1200/10003:
#0: ffffffff9009cba8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff8880552466e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2410
#2: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_expkey_get_reqs_dumpit+0xfd/0xd40 fs/nfsd/export.c:347
2 locks held by syz.4.2036/12855:
#0: ffffffff9009cba8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2114
2 locks held by syz.6.2409/14205:
#0: ffffffff9009cba8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964
1 lock held by syz.5.2715/15245:
#0: ffff88807f2d8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline]
#0: ffff88807f2d8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678
9 locks held by syz.7.2719/15259:
2 locks held by syz-executor/15278:
#0: ffffffff8f798fc8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8f798fc8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8f798fc8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595
#1: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#1: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4194
1 lock held by syz.0.2730/15313:
#0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
#0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3510
2 locks held by syz.8.2732/15329:
#0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810 net/core/rtnetlink.c:3666
#1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
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+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 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: 15259 Comm: syz.7.2719 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:tick_program_event+0x40/0x120 kernel/time/tick-oneshot.c:29
Code: 00 00 00 00 fc ff df 49 bc ff ff ff ff ff ff ff 7f e8 d4 37 0f 00 48 c7 c7 40 d3 ef 8b e8 a8 d8 17 0a 65 4c 8b 3d 08 71 b5 11 <4d> 89 fe 4c 89 e7 48 89 de e8 92 3c 0f 00 4c 39 e3 74 58 49 83 c7
RSP: 0018:ffffc90002fc6ae8 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000004f8f6e8000 RCX: 0000000000000203
RDX: ffffc90020dfc000 RSI: ffffffff8befd340 RDI: ffffffff8c4bd380
RBP: 0000000000000001 R08: ffffffff905776f7 R09: 1ffffffff20aeede
R10: dffffc0000000000 R11: fffffbfff20aeedf R12: 7fffffffffffffff
R13: dffffc0000000000 R14: ffff8880b862820f R15: ffff8880b8623c80
FS: 00007f7fb53536c0(0000) GS:ffff888124f5e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000d038 CR3: 000000004e78c000 CR4: 00000000003526f0
Call Trace:
hrtimer_rearm kernel/time/hrtimer.c:2141 [inline]
__hrtimer_rearm_deferred+0x26c/0x420 kernel/time/hrtimer.c:2161
hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline]
hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [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+0x8b7/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478
Code: 0f 84 44 ff ff ff e8 b2 6a 21 00 fb eb 44 e8 aa 6a 21 00 e8 85 ed 29 0a 4d 85 f6 74 94 e8 9b 6a 21 00 fb 48 c7 c7 a0 bf b4 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 fb 1b
RSP: 0018:ffffc90002fc6c60 EFLAGS: 00000246
RAX: ffffffff81a507a5 RBX: ffffffff81a5061f RCX: 0000000000080000
RDX: ffffc90020dfc000 RSI: 000000000007ffff RDI: ffffffff8eb4bfa0
RBP: ffffc90002fc6d10 R08: ffffffff905776f7 R09: 1ffffffff20aeede
R10: dffffc0000000000 R11: fffffbfff20aeedf R12: 0000000000000000
R13: 0000000000000018 R14: 0000000000000200 R15: 1ffff920005f8d90
_printk+0xdd/0x130 kernel/printk/printk.c:2504
netdev_info+0x11e/0x180 net/core/dev.c:13134
tun_net_xmit+0x9c9/0x1920 drivers/net/tun.c:1035
__netdev_start_xmit include/linux/netdevice.h:5424 [inline]
netdev_start_xmit include/linux/netdevice.h:5433 [inline]
xmit_one net/core/dev.c:3892 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3908
sch_direct_xmit+0x257/0x4c0 net/sched/sch_generic.c:372
__dev_xmit_skb net/core/dev.c:4214 [inline]
__dev_queue_xmit+0x1754/0x37f0 net/core/dev.c:4836
dev_queue_xmit include/linux/netdevice.h:3451 [inline]
neigh_hh_output include/net/neighbour.h:544 [inline]
neigh_output include/net/neighbour.h:558 [inline]
ip_finish_output2+0xbda/0x10b0 net/ipv4/ip_output.c:236
ip_send_skb+0x45/0xc0 net/ipv4/ip_output.c:1506
udp_send_skb+0x7f7/0xfb0 net/ipv4/udp.c:1162
udp_sendmsg+0x1971/0x2140 net/ipv4/udp.c:1444
sock_sendmsg_nosec+0x10e/0x180 net/socket.c:776
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmmsg+0x273/0x4d0 net/socket.c:2827
__do_sys_sendmmsg net/socket.c:2854 [inline]
__se_sys_sendmmsg net/socket.c:2851 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2851
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: 0033:0x7f7fb439de99
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:00007f7fb5353028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f7fb4625fa0 RCX: 00007f7fb439de99
RDX: 000000000800001d RSI: 0000200000007fc0 RDI: 0000000000000003
RBP: 00007f7fb4433eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7fb4626038 R14: 00007f7fb4625fa0 R15: 00007ffe416fdb68