INFO: task syz-executor:9295 blocked for more than 163 seconds.
Not tainted 6.16.0-rc5-next-20250711-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21704 pid:9295 tgid:9295 ppid:1 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
__schedule_loop kernel/sched/core.c:6775 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6790
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
kthread_stop+0x194/0x5f0 kernel/kthread.c:790
bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:438
__bch2_fs_read_only+0x47/0x5b0 fs/bcachefs/super.c:280
bch2_fs_read_only+0x42a/0xb00 fs/bcachefs/super.c:366
__bch2_fs_stop+0x100/0x900 fs/bcachefs/super.c:677
generic_shutdown_super+0x135/0x2c0 fs/super.c:643
bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2624
deactivate_locked_super+0xb9/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1378
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff402f8fc57
RSP: 002b:00007ffe67fb8638 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff403010925 RCX: 00007ff402f8fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe67fb86f0
RBP: 00007ffe67fb86f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe67fb9780
R13: 00007ff403010925 R14: 0000000000057ddd R15: 00007ffe67fb97c0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13c5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13c5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13c5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5613:
#0: ffff88814e1d90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5840:
3 locks held by kworker/1:5/5864:
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc900041bfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc900041bfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff888057381240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180 drivers/net/netdevsim/fib.c:1490
3 locks held by kworker/u8:12/7506:
#0: ffff88802f514148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88802f514148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000c3bfbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000c3bfbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
2 locks held by syz-executor/9295:
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888068100278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676
2 locks held by bch-copygc/loop/9862:
#0: ffff8880681043a0 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#0: ffff8880681043a0 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#0: ffff8880681043a0 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3300
#1: ffff888068126710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1208
3 locks held by kworker/u8:15/11027:
#0: ffff88802f514148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88802f514148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc90003757bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc90003757bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
1 lock held by syz.8.1141/11169:
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.9.1269/11774:
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff888053d5e0e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
3 locks held by syz-executor/12017:
#0: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f537a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
#1: ffff888032efd4e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50
#2: ffffffff8e1420f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e1420f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967
1 lock held by syz.6.1356/12144:
#0: ffffffff8e141fc0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3794
1 lock held by syz.2.1359/12183:
#0: ffffffff8e141fc0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3794
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 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: 7506 Comm: kworker/u8:12 Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: a9 71 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 0c 60 d6 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000c3bef30 EFLAGS: 00000002
RAX: 0000000000000020 RBX: 0000000000000020 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888024678237 R09: 1ffff110048cf046
R10: dffffc0000000000 R11: ffffffff854e0db0 R12: dffffc0000000000
R13: ffffffff99b4f8e3 R14: ffffffff99e54980 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125bc6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcace981ab8 CR3: 0000000071a2e000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:798 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3246 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x140d/0x1ba0 drivers/tty/serial/8250/8250_port.c:3396
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914
dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925
__netdev_printk+0x3d7/0x4d0 net/core/dev.c:12536
netdev_info+0x10a/0x160 net/core/dev.c:12591
nsim_udp_tunnel_set_port+0x26e/0x3e0 drivers/net/netdevsim/udp_tunnels.c:31
udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline]
udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:249 [inline]
__udp_tunnel_nic_device_sync+0xb0c/0x14d0 net/ipv4/udp_tunnel_nic.c:292
udp_tunnel_nic_device_sync_work+0x97/0xa50 net/ipv4/udp_tunnel_nic.c:740
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245