INFO: task syz.4.526:8897 blocked for more than 143 seconds.
Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.526 state:D stack:24408 pid:8897 tgid:8893 ppid:7891 task_flags:0x40054c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
__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+0x14d/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86c/0x2bd0 kernel/exit.c:964
do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
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: 0033:0x7f5b2ef8e929
RSP: 002b:00007f5b2fe3b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f5b2f1b6088 RCX: 00007f5b2ef8e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f5b2f1b6088
RBP: 00007f5b2f1b6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5b2f1b608c
R13: 0000000000000000 R14: 00007fffa149d3c0 R15: 00007fffa149d4a8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
4 locks held by kworker/u8:7/4550:
#0: ffff88801c6fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000e2b7d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffffffff90337c90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662
#3: ffffffff9034dce8 (rtnl_mutex){+.+.}-{4:4}, at: cangw_pernet_exit_batch+0x15/0xa0 net/can/gw.c:1288
2 locks held by kworker/u8:8/7539:
#0: ffff88801b889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffff8880b8424088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987
2 locks held by syz.1.392/7945:
#0: ffffffff903f24f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9ddc68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.4.526/8897:
#0: ffff88802adb20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802adb20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802adb20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88802adb20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9ddc68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.3.616/9325:
#0: ffffffff903f24f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9ddc68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc4/0x7a0 fs/nfsd/nfsctl.c:1770
2 locks held by getty/10909:
#0: ffff8880324f30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000489b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
3 locks held by syz.6.1035/11433:
#0: ffffffff90337c90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570
#1: ffffffff9034dce8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:174 [inline]
#1: ffffffff9034dce8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:249
#2: ffffffff8e5cfdb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304
2 locks held by syz.6.1035/11438:
#0: ffffffff90337c90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570
#1: ffffffff9034dce8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:174 [inline]
#1: ffffffff9034dce8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:249
2 locks held by syz.2.1036/11437:
#0: ffff88806dcd20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88806dcd20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88806dcd20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88806dcd20e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9ddc68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #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+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
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: 13 Comm: kworker/u8:1 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4871 [inline]
RIP: 0010:__lock_acquire+0x28e/0x1c90 kernel/locking/lockdep.c:5190
Code: 04 00 00 8b b5 e8 0a 00 00 45 84 ff 45 0f 44 fe 41 89 f6 41 83 ee 01 0f 88 db 0d 00 00 49 63 c6 48 8d 04 80 49 8d 04 c4 eb 12 <41> 83 ee 01 48 83 e8 28 41 83 fe ff 0f 84 8f 04 00 00 0f b6 50 21
RSP: 0018:ffffc900001279e8 EFLAGS: 00000046
RAX: ffff88801e6a8b18 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88801e6a8b40
RBP: ffff88801e6a8000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000050 R11: 0000000000000001 R12: ffff88801e6a8af0
R13: ffff88801e6a8b40 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812475f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f74f7181178 CR3: 0000000077c5c000 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]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0x16a/0x1030 net/batman-adv/network-coding.c:719
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+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245