INFO: task syz-executor:5603 blocked for more than 142 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21472 pid:5603 tgid:5603 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 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+0xccb/0x1bd0 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1372
deactivate_locked_super+0xbd/0x130 fs/super.c:586
deactivate_super fs/super.c:614 [inline]
deactivate_super+0xea/0x110 fs/super.c:610
cleanup_mnt+0xb7/0x160 fs/namespace.c:1392
task_work_run+0x150/0x240 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+0x1d8/0x700 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+0x661/0x790 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f51f0b9f417
RSP: 002b:00007ffdda39b598 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f51f0b9f417
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdda39b650
RBP: 00007ffdda39b650 R08: 00007ffdda39c650 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdda39c6e0
R13: 00007f51f0c34ccb R14: 0000000000062732 R15: 00007ffdda39c720
INFO: task syz.1.747:8789 blocked for more than 142 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.747 state:D stack:26888 pid:8789 tgid:8785 ppid:5604 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 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+0xccb/0x1bd0 kernel/locking/mutex.c:821
write_versions+0x9d/0xba0 fs/nfsd/nfsctl.c:708
nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:114
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb10219e1d9
RSP: 002b:00007fb103099028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb102426090 RCX: 00007fb10219e1d9
RDX: 0000000000000003 RSI: 00002000000004c0 RDI: 0000000000000006
RBP: 00007fb102235888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb102426128 R14: 00007fb102426090 R15: 00007ffc44585d58
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#1:
#0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by khugepaged/38: 1, last CPU#0:
#0: ffffffff8ff56d60 (lock#5){+.+.}-{4:4}, at: __lru_add_drain_all+0xcf/0x820 mm/folio.c:823
locks held by kworker/0:3/2246: 3, last CPU#0:
#0: ffff888055c25940 ((wq_completion)wg-crypt-wg0#8){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90007027d08 ((work_completion)(&peer->transmit_packet_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: __run_hrtimer kernel/time/hrtimer.c:2078 [inline]
#2: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: __hrtimer_run_queues+0x1b7/0x9c0 kernel/time/hrtimer.c:2131
locks held by getty/5358: 2, on CPU#0:
#0: ffff888038dc20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by syz-executor/5602: 4, last CPU#0:
#0: ffffffff8ff3de10 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff8ff3de10 (dup_mmap_sem){++++}-{0:0}, at: copy_mm kernel/fork.c:1595 [inline]
#0: ffffffff8ff3de10 (dup_mmap_sem){++++}-{0:0}, at: copy_process+0x4816/0x8380 kernel/fork.c:2311
#1: ffff88802e89f180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#1: ffff88802e89f180 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x127/0x2370 mm/mmap.c:1716
#2: ffff888075ba4080 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
#2: ffff888075ba4080 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1c9/0x2370 mm/mmap.c:1723
#3: ffff88807144ccd0 (&anon_vma->rwsem){++++}-{4:4}, at: anon_vma_lock_write mm/internal.h:295 [inline]
#3: ffff88807144ccd0 (&anon_vma->rwsem){++++}-{4:4}, at: anon_vma_clone+0x41a/0xca0 mm/rmap.c:357
locks held by syz-executor/5603: 2, on CPU#1:
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: deactivate_super fs/super.c:613 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:610
#1: ffffffff90289ca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by kworker/0:4/5610: 5, on CPU#0:
#0: ffff8880226a5d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90003b8fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802bf421d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802bf421d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4420 drivers/usb/core/hub.c:5917
#3: ffff888055a9a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff888055a9a1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073
#4: ffff8880270331a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff8880270331a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073
locks held by syz.1.747/8787: 3, on CPU#1:
#0: ffff88803680c9b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff888075bac460 (sb_writers#18){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff90289ca0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
locks held by syz.1.747/8789: 3, on CPU#1:
#0: ffff88807c2c37b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff888075bac460 (sb_writers#18){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff90289ca0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x9d/0xba0 fs/nfsd/nfsctl.c:708
locks held by syz.2.784/8925: 3, on CPU#1:
#0: ffff8880354b7b30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88807bdb2460 (sb_writers#18){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff90289ca0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
locks held by syz.2.784/8926: 3, on CPU#0:
#0: ffff8880354b6470 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88807bdb2460 (sb_writers#18){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff90289ca0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x9d/0xba0 fs/nfsd/nfsctl.c:708
locks held by syz-executor/8937: 1, last CPU#1:
#0: ffff88802e3c4460 (sb_writers#6){.+.+}-{0:0}, at: filename_unlinkat+0x1ad/0x730 fs/namei.c:5725
locks held by syz.5.892/9481: 1, on CPU#0:
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.9.1078/10210: 1, on CPU#1:
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.9.1078/10212: 1, on CPU#0:
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.9.1078/10220: 1, on CPU#0:
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff88807d3460e8 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.7.1082/10218: 2, on CPU#0:
#0: ffff88807fe1e9c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff88807fe1e9c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:734
#1: ffffffff8fdf84a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 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: 9579 Comm: kworker/u8:25 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: bat_events batadv_bla_periodic_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4923 [inline]
RIP: 0010:__lock_acquire+0x4ee/0x1f40 kernel/locking/lockdep.c:5238
Code: 02 44 0f 44 f0 41 83 c5 01 48 83 c3 28 45 3b ac 24 a0 0b 00 00 7d 27 0f b7 43 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 d2 12 ab 15 <72> ac 8b 05 ea be b3 1a 85 c0 0f 84 05 03 00 00 31 c9 eb aa 48 89
RSP: 0018:ffffc900000073d0 EFLAGS: 00000003
RAX: 0000000000000007 RBX: ffff888029cf31a8 RCX: 0000000000000000
RDX: 0000000000000007 RSI: ffff888029cf31a8 RDI: 0000000000000020
RBP: ffff888029cf31d0 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000001 R12: ffff888029cf2580
R13: 0000000000000003 R14: 0000000000000003 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888122946000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb4fdf556c8 CR3: 000000007d0ba000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000063235cd5
DR3: 0000000000007000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire kernel/locking/lockdep.c:5942 [inline]
lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
slab_free mm/slub.c:6509 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6802
skb_kfree_head net/core/skbuff.c:1083 [inline]
skb_free_head+0xb9/0x160 net/core/skbuff.c:1095
skb_release_data+0x659/0x860 net/core/skbuff.c:1122
skb_release_all net/core/skbuff.c:1197 [inline]
__kfree_skb net/core/skbuff.c:1211 [inline]
consume_skb net/core/skbuff.c:1448 [inline]
consume_skb+0xc4/0x110 net/core/skbuff.c:1442
arp_process+0xa19/0x2440 net/ipv4/arp.c:942
NF_HOOK include/linux/netfilter.h:325 [inline]
NF_HOOK include/linux/netfilter.h:319 [inline]
arp_rcv+0x3ba/0x500 net/ipv4/arp.c:996
__netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6297
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6410
process_backlog+0x487/0x1600 net/core/dev.c:6761
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:8050
handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
do_softirq kernel/softirq.c:546 [inline]
do_softirq+0xaf/0xf0 kernel/softirq.c:533
__local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
netif_rx net/core/dev.c:5870 [inline]
netif_rx+0x93/0xb0 net/core/dev.c:5859
batadv_bla_send_claim+0x4e5/0x1190 net/batman-adv/bridge_loop_avoidance.c:441
batadv_bla_send_announce+0x130/0x190 net/batman-adv/bridge_loop_avoidance.c:675
batadv_bla_periodic_work+0x428/0xa10 net/batman-adv/bridge_loop_avoidance.c:1530
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
process_scheduled_works kernel/workqueue.c:3479 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245