INFO: task kworker/u8:16:6932 blocked for more than 143 seconds.
Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:16 state:D stack:21400 pid:6932 tgid:6932 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
afs_cell_purge+0x3d9/0x540 fs/afs/cell.c:893
afs_net_exit+0x50/0x100 fs/afs/main.c:146
ops_exit_list net/core/net_namespace.c:172 [inline]
cleanup_net+0x71a/0xbd0 net/core/net_namespace.c:654
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
#0: ffff8880b8839b58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:613
#1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffff8880b8825558 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1159
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by getty/5577:
#0: ffff88814d5fa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900030062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/u8:16/6932:
#0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000dfa7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000dfa7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e6cd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
2 locks held by kworker/0:1/8676:
#0: ffff88801a078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc900041f7c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900041f7c60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
2 locks held by kworker/u8:17/9055:
4 locks held by syz-executor/17702:
#0: ffff888075120d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
#0: ffff888075120d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678
#1: ffff888075120078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213
#2: ffffffff8f459a08 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2066 [inline]
#2: ffffffff8f459a08 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2701
#3: ffff888028f06b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1761
1 lock held by syz-executor/17819:
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
2 locks held by sed/18711:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
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: 18711 Comm: sed Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:find_stack lib/stackdepot.c:552 [inline]
RIP: 0010:stack_depot_save_flags+0x163/0x910 lib/stackdepot.c:619
Code: c8 31 c5 c1 c0 18 29 c5 48 8b 05 f8 e2 c5 14 8b 0d ea e2 c5 14 21 e9 48 c1 e1 04 4c 8d 3c 08 65 ff 05 c1 21 88 0d 4c 8b 2c 08 <4d> 39 fd 74 09 44 88 24 24 45 89 d4 eb 35 45 31 ed e9 87 00 00 00
RSP: 0018:ffffc9000af4f750 EFLAGS: 00000282
RAX: ffff88823ae00000 RBX: 0000000000000000 RCX: 0000000000a587b0
RDX: 00000000c1804108 RSI: 0000000000000000 RDI: 000000000750e403
RBP: 000000006a1a587b R08: 0000000034c1de1d R09: 000000000521c805
R10: 000000000000000c R11: ffffffff81ce8306 R12: ffffea0001a00100
R13: ffff88807e3bfa10 R14: ffffc9000af4f7c0 R15: ffff88823b8587b0
FS: 0000000000000000(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3556d1c378 CR3: 000000002e15d000 CR4: 0000000000350ef0
Call Trace:
kasan_save_stack+0x4d/0x60 mm/kasan/common.c:48
kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2359 [inline]
slab_free mm/slub.c:4656 [inline]
kmem_cache_free+0x2ee/0x3f0 mm/slub.c:4758
exit_mmap+0x593/0xba0 mm/mmap.c:1309
__mmput+0x118/0x420 kernel/fork.c:1379
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f83afc42a90
Code: Unable to access opcode bytes at 0x7f83afc42a66.
RSP: 002b:00007ffd54124628 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f83afd33860 RCX: 00007f83afc42a90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00007f83afd33860 R08: 00007ffd541244a0 R09: 00007ffd54124580
R10: 00007ffd541244e0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f83afd37658 R15: 0000000000000001