INFO: task syz.3.835:7862 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.835 state:D stack:27016 pid:7862 ppid:5775 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
write_versions+0x96/0xe00 fs/nfsd/nfsctl.c:676
nfsctl_transaction_write+0x10c/0x150 fs/nfsd/nfsctl.c:113
vfs_write+0x299/0x9a0 fs/read_write.c:582
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3f9179e0d9
RSP: 002b:00007f3f92712028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3f91a25fa0 RCX: 00007f3f9179e0d9
RDX: 0000000000000005 RSI: 0000200000000b00 RDI: 0000000000000003
RBP: 00007f3f91835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f91a26038 R14: 00007f3f91a25fa0 R15: 00007ffdc8f8f068
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:2/34:
3 locks held by kworker/u4:3/49:
#0: ffff88802c431d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff88802c431d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc90000b9fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc90000b9fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4730
3 locks held by kworker/u4:4/59:
#0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc900015a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc900015a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
3 locks held by kworker/1:2/1190:
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc900046e7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc900046e7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by kworker/u4:6/2913:
5 locks held by kworker/u4:7/3491:
#0: ffff888140045138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888140045138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc9000c93fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc9000c93fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffffffff8e3c9f50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606
#3: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xf2/0xa00 net/core/dev.c:11764
#4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by dhcpcd/5432:
#0: ffff8880196da690 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0xf4/0x7a0 net/netlink/af_netlink.c:2341
#1: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0x77c/0xec0 net/netlink/af_netlink.c:2268
2 locks held by getty/5530:
#0: ffff88802cfda0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032832f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by syz-executor/5774:
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x53/0x1a0 fs/nfsd/nfssvc.c:638
3 locks held by syz.0.729/7619:
#0: ffff8880262d80c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88802be32418 (sb_writers#28){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843
3 locks held by syz.3.835/7862:
#0: ffff888023eb05c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff888021ba4418 (sb_writers#28){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x96/0xe00 fs/nfsd/nfsctl.c:676
3 locks held by kworker/0:5/7958:
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc900037afd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc900037afd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
3 locks held by syz.4.1153/8675:
#0: ffff888020ebe848 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88802e57c418 (sb_writers#28){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843
3 locks held by syz.5.1237/8925:
#0: ffff88802de2f9c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff888026ba6418 (sb_writers#28){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x65/0xab0 fs/nfsd/nfssvc.c:788
2 locks held by syz-executor/9216:
#0: ffff888024be20e0 (&type->s_umount_key#93){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888024be20e0 (&type->s_umount_key#93){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888024be20e0 (&type->s_umount_key#93){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x53/0x1a0 fs/nfsd/nfssvc.c:638
1 lock held by syz.9.1466/9834:
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: super_lock+0x189/0x390 fs/super.c:117
1 lock held by syz.9.1466/9845:
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88801c36e0e0 (&type->s_umount_key#93){++++}-{3:3}, at: super_lock+0x189/0x390 fs/super.c:117
1 lock held by syz-executor/10565:
#0: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6481
1 lock held by syz-executor/10600:
#0: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8e3d6f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6481
2 locks held by syz.3.1701/10662:
#0: ffff888027c6c5c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffffffff8d3e1748 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x96/0xe00 fs/nfsd/nfsctl.c:676
4 locks held by syz.8.1709/10713:
#0: ffff88806600ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff88806600ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x500 net/bluetooth/hci_core.c:2709
#1: ffff88806600c0b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x552/0x1130 net/bluetooth/hci_sync.c:5326
#2: ffffffff8e544888 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2016 [inline]
#2: ffffffff8e544888 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0x99/0x220 net/bluetooth/hci_conn.c:2571
#3: ffff888024e20b38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x7b/0x630 net/bluetooth/l2cap_core.c:1793
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 983 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
RIP: 0010:unwind_next_frame+0xf0e/0x2990 arch/x86/kernel/unwind_orc.c:585
Code: 20 c1 4d 39 f7 0f 97 c0 84 c1 4c 89 f5 0f 84 33 02 00 00 48 89 6c 24 30 48 8d 45 08 48 39 d8 0f 97 c1 4c 39 f8 0f 96 c0 84 c1 <48> 8b 6c 24 10 4d 8d 75 10 0f 84 bc 05 00 00 e8 7e bf 4b 00 49 bf
RSP: 0018:ffffc900041a75d8 EFLAGS: 00000202
RAX: ffffc900041a7a01 RBX: ffffc900041a0000 RCX: 0000000000000001
RDX: ffff888022360000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900041a7a58 R08: ffff888022360000 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: 1ffff92000834ed7
R13: ffffc900041a76a8 R14: ffffc900041a7a58 R15: ffffc900041a8000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31120ff8 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
<TASK>
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x290 mm/slub.c:3852
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x723/0xa90 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2657 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>