INFO: task syz-executor:12821 blocked for more than 143 seconds.
Tainted: G S syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21800 pid:12821 ppid:1 flags:0x00004004
Call Trace:
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
nfsd_shutdown_threads+0x53/0x1a0 fs/nfsd/nfssvc.c:638
nfsd_umount+0x42/0xc0 fs/nfsd/nfsctl.c:1464
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x3d7/0x460 fs/namespace.c:1259
task_work_run+0x1d4/0x260 kernel/task_work.c:245
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1cd739f317
RSP: 002b:00007ffdf6699ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f1cd7434474 RCX: 00007f1cd739f317
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf6699fb0
RBP: 00007ffdf6699fb0 R08: 00007ffdf669afb0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdf669b040
R13: 00007f1cd7434474 R14: 000000000007b6b6 R15: 00007ffdf669b080
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
3 locks held by kworker/u4:8/2920:
2 locks held by kworker/u4:9/2925:
2 locks held by kworker/0:3/5815:
#0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc9000495fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc9000495fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
4 locks held by kworker/0:6/5837:
3 locks held by kworker/0:7/10143:
#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: ffffc90003467d00 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc90003467d00 (xfrm_state_gc_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:292 [inline]
#2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by getty/12400:
#0: ffff88814c7550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900052212f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by syz-executor/12821:
#0: ffff88801df640e0 (&type->s_umount_key#104){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88801df640e0 (&type->s_umount_key#104){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88801df640e0 (&type->s_umount_key#104){+.+.}-{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.6.2769/13998:
#0: ffff88802d677c48 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff888031232418 (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
3 locks held by syz.3.3375/15840:
#0: ffff88805a86cd48 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88802794a418 (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
2 locks held by syz-executor/16166:
#0: ffff88804535e0e0 (&type->s_umount_key#104){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88804535e0e0 (&type->s_umount_key#104){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88804535e0e0 (&type->s_umount_key#104){+.+.}-{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
4 locks held by kworker/u4:7/17003:
1 lock held by syz.7.3836/17120:
1 lock held by syz.2.3838/17138:
2 locks held by sed/17137:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Tainted: G S syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2920 Comm: kworker/u4:8 Tainted: G S syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x393/0x7d80 kernel/locking/lockdep.c:5070
Code: 83 fd 31 48 89 54 24 30 0f 83 fe 15 00 00 4b 8d 44 ad 00 49 8d 1c c7 49 8d 44 c7 20 48 89 44 24 18 48 c1 e8 03 48 89 44 24 58 <42> 0f b6 04 00 84 c0 0f 85 f7 15 00 00 4c 8b 6d 18 b8 00 e0 ff ff
RSP: 0018:ffffc9000ba677c0 EFLAGS: 00000802
RAX: 1ffff110057e516b RBX: ffff88802bf28b38 RCX: ffff88802bf28000
RDX: 0000000000000021 RSI: 0000000000000021 RDI: ffff88802bf28b30
RBP: ffffc9000ba67a08 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d18ee6 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: ffff88802bf28ae8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f47baab8fe8 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x600 net/batman-adv/network-coding.c:719
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