INFO: task syz.5.2249:15210 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.2249 state:D stack:27240 pid:15210 tgid:15209 ppid:9325 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
device_lock include/linux/device.h:911 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
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: 0033:0x7f4975f8d510
RSP: 002b:00007f4976e8cb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f4975f8d510
RDX: 0000000000000002 RSI: 00007f4976e8cc10 RDI: 00000000ffffff9c
RBP: 00007f4976e8cc10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f49761d6038 R14: 00007f49761d5fa0 R15: 00007f49762ffa28
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900000e7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900000e7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
3 locks held by kworker/0:1/10:
1 lock held by khungtaskd/31:
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5629:
#0: ffff88814dea40a0 (&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
3 locks held by kworker/0:3/5863:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
#1: ffffc90003f6fbc0 ((work_completion)(&vb->update_balloon_size_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003f6fbc0 ((work_completion)(&vb->update_balloon_size_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88802074c2e0 (&vb->balloon_lock){+.+.}-{4:4}, at: fill_balloon drivers/virtio/virtio_balloon.c:268 [inline]
#2: ffff88802074c2e0 (&vb->balloon_lock){+.+.}-{4:4}, at: update_balloon_size_func+0x399/0xb00 drivers/virtio/virtio_balloon.c:567
4 locks held by udevd/5880:
#0: ffff88802e7640a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff888056dd4488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff888052be84b8 (kn->active#22){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888052be84b8 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff88803115c198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
#3: ffff88803115c198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
6 locks held by kworker/1:7/5956:
#0: ffff888144af4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888144af4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000457fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000457fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff888028209198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff888028209198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88803115c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#3: ffff88803115c198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff88807d001160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88807d001160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#5: ffffffff8dfe0510 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214
3 locks held by kworker/0:7/5992:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
#1: ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffffe8ffffc23258 (&ACCESS_PRIVATE(sdp, lock)){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
#2: ffffe8ffffc23258 (&ACCESS_PRIVATE(sdp, lock)){....}-{3:3}, at: srcu_invoke_callbacks+0x30b/0x450 kernel/rcu/srcutree.c:1816
1 lock held by syz.0.1635/12736:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433
2 locks held by syz.2.1646/12794:
1 lock held by syz-executor/13214:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433
1 lock held by syz.1.1957/14109:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433
3 locks held by kworker/u8:9/14804:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
#1: ffffc90012aefbc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90012aefbc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
#2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: batadv_nc_worker+0xd2/0x610 net/batman-adv/network-coding.c:719
1 lock held by syz.5.2249/15210:
#0: ffff888028209198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#0: ffff888028209198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
2 locks held by syz-executor/15394:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433
#1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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+0x436/0x7d0 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: 1142 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x2f9/0xd20 kernel/locking/lockdep.c:5178
Code: 0d c1 e6 0e 09 d6 8b 54 24 1c c1 e2 0f 0f b7 d2 09 f2 41 83 e4 03 41 c1 e4 10 41 09 d4 8b 54 24 0c 83 e2 01 c1 e2 12 44 09 e2 <41> c1 e6 14 41 09 d6 8b 54 24 10 c1 e2 13 c1 e5 15 09 d5 09 cd 44
RSP: 0018:ffffc90003d9f880 EFLAGS: 00000006
RAX: 000000000000000a RBX: ffffffff8e13a0e0 RCX: 0000000000000007
RDX: 0000000000020000 RSI: 0000000000000000 RDI: ffff888026ba1e00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b48490a
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: 0000000000020000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888026ba28f0
FS: 0000000000000000(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055df9e14d000 CR3: 000000007eede000 CR4: 00000000003526f0
DR0: 0000040000000000 DR1: 000000000000064f DR2: 0000000000000002
DR3: 0000000040000006 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_process_nc_paths+0xdb/0x3a0 net/batman-adv/network-coding.c:687
batadv_nc_worker+0x429/0x610 net/batman-adv/network-coding.c:728
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245