INFO: task syz.3.3843:21310 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3843 state:D stack:25664 pid:21310 tgid:21308 ppid:17775 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f547499ce59
RSP: 002b:00007f547588d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5474c15fa0 RCX: 00007f547499ce59
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007f5474a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5474c16038 R14: 00007f5474c15fa0 R15: 00007ffd644f2728
Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5382:
#0: ffff888032aed0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by kworker/1:10/7745:
#0: ffff8880b873aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
3 locks held by kworker/u8:13/11092:
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000352fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000352fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8fdd0240 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by syz.2.3507/20023:
#0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
2 locks held by syz.3.3843/21310:
#0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728
2 locks held by syz.6.4131/22394:
#0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
2 locks held by syz.5.4139/22428:
#0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
1 lock held by syz.8.4866/25270:
1 lock held by syz.4.4896/25371:
2 locks held by syz.0.4899/25381:
#0: ffffffff8fdd0240 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdd0240 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438
#1: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
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+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11088 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4313 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xb1/0x260 kernel/locking/lockdep.c:4410
Code: 00 65 48 8b 1d 48 bf 97 11 48 8b 83 80 0b 00 00 48 89 83 68 0b 00 00 48 c7 c7 e0 0b fc 8d e8 b6 30 07 0a 65 ff 05 cf 04 98 11 <83> bb 88 0b 00 00 00 0f 8e d1 00 00 00 49 89 de 49 81 c6 90 0b 00
RSP: 0018:ffffc900035af738 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff88802d6b1ec0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8dfc0be0 RDI: ffffffff8c28af60
RBP: ffffc900035af838 R08: ffffffff9030bff7 R09: 1ffffffff20617fe
R10: dffffc0000000000 R11: fffffbfff20617ff R12: ffff88813fe19a08
R13: ffffc900035af7d0 R14: ffff88813fe199c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555d9f81b660 CR3: 0000000075da8000 CR4: 00000000003526f0
Call Trace:
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline]
_raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:198
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
get_partial_node_bulk mm/slub.c:3771 [inline]
__refill_objects_node+0x211/0x5c0 mm/slub.c:7107
refill_objects+0x62/0x3d0 mm/slub.c:7242
refill_sheaf mm/slub.c:2816 [inline]
__pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
alloc_from_pcs mm/slub.c:4749 [inline]
slab_alloc_node mm/slub.c:4883 [inline]
__do_kmalloc_node mm/slub.c:5294 [inline]
__kmalloc_node_track_caller_noprof+0x572/0x7b0 mm/slub.c:5407
kmalloc_reserve net/core/skbuff.c:635 [inline]
__alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x29a/0xb90 drivers/net/netdevsim/dev.c:922
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 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