INFO: task syz-executor:9237 blocked for more than 143 seconds.
Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23960 pid:9237 tgid:9237 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5401 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6790
__schedule_loop kernel/sched/core.c:6868 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6883
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6940
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xc1/0x1a0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xde/0x100 fs/super.c:503
cleanup_mnt+0x225/0x450 fs/namespace.c:1417
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f281db8fc57
RSP: 002b:00007fff2390fb68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f281db8fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff2390fc20
RBP: 00007fff2390fc20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff23910cb0
R13: 00007f281dc10925 R14: 00000000000765c0 R15: 00007fff23910cf0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c4d00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c4d00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c4d00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:8/3002:
#0: ffff88801b889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffff8880b8524088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987
4 locks held by kworker/u8:13/7233:
#0: ffff88801c6fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000be67d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffffffff9034e110 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662
#3: ffffffff90364168 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:174 [inline]
#3: ffffffff90364168 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:249
4 locks held by kworker/u8:16/8073:
2 locks held by syz-executor/9237:
#0: ffff888058f4c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888058f4c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888058f4c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888058f4c0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/10486:
#0: ffff88802a5fc0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802a5fc0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802a5fc0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88802a5fc0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by getty/11446:
#0: ffff88814ca0b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90003a812f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz.0.1085/11994:
#0: ffffffff90408970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922
1 lock held by syz-executor/13105:
#0: ffffffff8e5d02f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336
2 locks held by syz.6.1277/13108:
#0: ffffffff90408970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc4/0x7a0 fs/nfsd/nfsctl.c:1770
2 locks held by syz.7.1377/13648:
#0: ffffffff90408970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922
2 locks held by syz.3.1404/13784:
#0: ffffffff90408970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.9.1414/13853:
#0: ffffffff90408970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc4/0x7a0 fs/nfsd/nfsctl.c:1770
2 locks held by syz-executor/13996:
#0: ffff8880124420e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880124420e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880124420e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880124420e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz-executor/14090:
#0: ffff8880321000e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880321000e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880321000e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880321000e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de688 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
1 lock held by dhcpcd/14643:
#0: ffff888033dcc258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
#0: ffff888033dcc258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3252
1 lock held by dhcpcd/14644:
#0: ffff88807ce06258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
#0: ffff88807ce06258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3252
1 lock held by dhcpcd/14645:
#0: ffff88807e2e4258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
#0: ffff88807e2e4258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3252
4 locks held by rm/14657:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:470
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
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: 8073 Comm: kworker/u8:16 Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4882 [inline]
RIP: 0010:__lock_acquire+0x336/0x1c90 kernel/locking/lockdep.c:5190
Code: d0 41 83 c6 01 44 3b b5 e8 0a 00 00 7d 30 49 63 c6 48 8d 04 80 41 0f b7 44 c4 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 5a bf 3e 14 <72> ab 8b 05 32 6a 47 19 85 c0 0f 84 f8 00 00 00 31 c9 eb a9 44 38
RSP: 0018:ffffc9000fa37538 EFLAGS: 00000007
RAX: 0000000000000cb1 RBX: 0000000000000004 RCX: ffffffff95dcce28
RDX: 0000000000000005 RSI: 0000000000000004 RDI: ffff888029b7e590
RBP: ffff888029b7da00 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000000a0 R11: 0000000000000001 R12: ffff888029b7e4f0
R13: ffff888029b7e590 R14: 0000000000000002 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124821000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f48ca9c5000 CR3: 000000000e382000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5871 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2381 [inline]
slab_free mm/slub.c:4643 [inline]
kfree+0x2b4/0x4d0 mm/slub.c:4842
skb_kfree_head net/core/skbuff.c:1048 [inline]
skb_free_head+0x114/0x210 net/core/skbuff.c:1060
skb_release_data+0x776/0x9c0 net/core/skbuff.c:1087
skb_release_all net/core/skbuff.c:1152 [inline]
__kfree_skb net/core/skbuff.c:1166 [inline]
consume_skb net/core/skbuff.c:1398 [inline]
consume_skb+0xbf/0x100 net/core/skbuff.c:1392
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x8bd/0xcf0 drivers/net/netdevsim/dev.c:851
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245