INFO: task syz.1.960:9621 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.960 state:D stack:26184 pid:9621 tgid:9619 ppid:5811 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
sync_bdevs+0x153/0x480 block/bdev.c:1304
ksys_sync+0xb0/0xf0 fs/sync.c:105
__do_sys_sync+0xe/0x20 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f366559c819
RSP: 002b:00007f3666438028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f3665815fa0 RCX: 00007f366559c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3665815fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3665816038 R14: 00007f3665815fa0 R15: 00007ffef30eebe8
Showing all locks held in the system:
1 lock held by ksoftirqd/1/23:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e77a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e77a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e77a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/1:1H/1673:
2 locks held by getty/5571:
#0: ffff888034b2c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by udevd/5810:
#0: ffff888028373358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by udevd/5824:
#0: ffff888028371358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by udevd/5829:
#0: ffff8880281b1358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
6 locks held by kworker/1:6/5927:
1 lock held by udevd/7051:
#0: ffff8880281b5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by udevd/7763:
#0: ffff888028271358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
5 locks held by kworker/0:5/9280:
#0: ffff8880232e2148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263
#1: ffffc90005377d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264
#2: ffff88802b6391e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88802b6391e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88805bb0d1e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#3: ffff88805bb0d1e0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#4: ffff88801bbcd1a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#4: ffff88801bbcd1a8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
1 lock held by syz.1.960/9621:
#0: ffff888028371358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
1 lock held by syz.4.1299/11007:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
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: 567 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4703 [inline]
RIP: 0010:__lock_acquire+0x4fd/0x2630 kernel/locking/lockdep.c:5221
Code: 85 c9 0f 84 97 01 00 00 c7 44 24 08 00 00 00 00 48 89 13 8b 85 50 0b 00 00 85 c0 74 18 48 8b 3c 24 48 8d 04 80 0f b6 44 c7 f9 <32> 43 21 a8 60 0f 85 70 08 00 00 48 89 d0 89 d6 48 c1 e8 20 89 c7
RSP: 0018:ffffc90003ef7960 EFLAGS: 00000006
RAX: 0000000000000007 RBX: ffff888026a98bd0 RCX: 0000000000000003
RDX: c9ce84ae13f86e38 RSI: ffff888026a98bd0 RDI: ffff888026a98b58
RBP: ffff888026a98000 R08: 0000000000000000 R09: 0000000000000007
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000007 R14: 0000000000000003 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff888124338000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd6e3e92f8 CR3: 000000000e598000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:764 [inline]
batadv_iv_ogm_schedule_buff+0x5da/0x1520 net/batman-adv/bat_iv_ogm.c:836
batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:876 [inline]
batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:869 [inline]
batadv_iv_send_outstanding_bat_ogm_packet+0x6e0/0x860 net/batman-adv/bat_iv_ogm.c:1712
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3288
process_scheduled_works kernel/workqueue.c:3371 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3452
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245