INFO: task syz.9.7114:24788 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.7114 state:D stack:27664 pid:24788 tgid:24787 ppid:22533 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
__mutex_lock_common kernel/locking/mutex.c:680 [inline]
__mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:764
nbd_start_device_ioctl drivers/block/nbd.c:1552 [inline]
__nbd_ioctl drivers/block/nbd.c:1612 [inline]
nbd_ioctl+0xb0a/0xeb0 drivers/block/nbd.c:1652
blkdev_ioctl+0x5a5/0x6d0 block/ioctl.c:710
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f587ab8e9a9
RSP: 002b:00007f587b9f3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f587adb5fa0 RCX: 00007f587ab8e9a9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f587ac10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f587adb5fa0 R15: 00007ffdce484c18
INFO: task syz.9.7114:24789 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.7114 state:D stack:28936 pid:24789 tgid:24787 ppid:22533 task_flags:0x480140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
blk_mq_freeze_queue_wait+0xf4/0x170 block/blk-mq.c:190
blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
__nbd_ioctl drivers/block/nbd.c:1595 [inline]
nbd_ioctl+0x583/0xeb0 drivers/block/nbd.c:1652
blkdev_ioctl+0x5a5/0x6d0 block/ioctl.c:710
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f587ab8e9a9
RSP: 002b:00007f587b9d2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f587adb6080 RCX: 00007f587ab8e9a9
RDX: 0000000000000004 RSI: 000000000000ab00 RDI: 0000000000000003
RBP: 00007f587ac10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f587adb6080 R15: 00007ffdce484c18
INFO: task syz.9.7114:24793 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.7114 state:D stack:28168 pid:24793 tgid:24787 ppid:22533 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
__mutex_lock_common kernel/locking/mutex.c:680 [inline]
__mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:764
nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1645
blkdev_ioctl+0x5a5/0x6d0 block/ioctl.c:710
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f587ab8e9a9
RSP: 002b:00007f587b990038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f587adb6240 RCX: 00007f587ab8e9a9
RDX: 0000000000000000 RSI: 000000000000ab04 RDI: 0000000000000003
RBP: 00007f587ac10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f587adb6240 R15: 00007ffdce484c18
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
5 locks held by kworker/1:0/24:
#0: ffff888144ab0d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888144ab0d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900001e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900001e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff888145724198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff888145724198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88807c17a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#3: ffff88807c17a198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff8880577da160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff8880577da160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
1 lock held by khungtaskd/31:
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
1 lock held by klogd/5208:
2 locks held by getty/5616:
#0: ffff888033a560a0 (&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
5 locks held by kworker/1:6/5962:
#0: ffff888144ab0d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888144ab0d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90004667bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90004667bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff888028324198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff888028324198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff888028327518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline]
#3: ffff888028327518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline]
#3: ffff888028327518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
#3: ffff888028327518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline]
#3: ffff888028327518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b8/0x4a20 drivers/usb/core/hub.c:5952
#4: ffff888027ec1e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#4: ffff888027ec1e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
#4: ffff888027ec1e68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline]
#4: ffff888027ec1e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e5/0x4a20 drivers/usb/core/hub.c:5952
1 lock held by udevd/5969:
#0: ffff8880256c8358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by udevd/10147:
#0: ffff8880250fc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.4.5838/20374:
#0: ffff8880547860e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.9.7114/24788:
#0: ffff8880256b4a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_start_device_ioctl drivers/block/nbd.c:1552 [inline]
#0: ffff8880256b4a30 (&nbd->config_lock){+.+.}-{4:4}, at: __nbd_ioctl drivers/block/nbd.c:1612 [inline]
#0: ffff8880256b4a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0xb0a/0xeb0 drivers/block/nbd.c:1652
3 locks held by syz.9.7114/24789:
#0: ffff8880256b4a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1645
#1: ffff888143bd1e18 (&q->q_usage_counter(io)#59){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
#1: ffff888143bd1e18 (&q->q_usage_counter(io)#59){++++}-{0:0}, at: nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
#2: ffff888143bd1e50 (&q->q_usage_counter(queue)#11){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
#2: ffff888143bd1e50 (&q->q_usage_counter(queue)#11){+.+.}-{0:0}, at: nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
1 lock held by syz.9.7114/24793:
#0: ffff8880256b4a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1645
2 locks held by syz.1.8052/27714:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4785 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4878 [inline]
RIP: 0010:__lock_acquire+0x49c/0xd20 kernel/locking/lockdep.c:5190
Code: 60 00 00 74 cf eb 1c 48 c7 c7 30 e8 40 8e 48 89 de e8 b8 f9 67 03 48 8b 3c 24 41 8b 46 20 eb ca 41 89 ef 65 8b 05 80 d1 49 11 <85> c0 0f 84 02 01 00 00 41 b4 03 83 bf c0 0a 00 00 00 0f 84 d7 04
RSP: 0018:ffffc900001178f0 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88801d2ada00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b4d0e32
R10: dffffc0000000000 R11: ffffffff8b4d0d60 R12: ffffffffffffffff
R13: 0000000000000001 R14: ffff88801d2ae540 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c45e7e7 CR3: 000000007c3b2000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
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+0xef/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/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