INFO: task syz.2.185:6613 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.185 state:D stack:23368 pid:6613 ppid:5779 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
blkdev_open+0x14e/0x360 block/fops.c:589
do_dentry_open+0x880/0x14b0 fs/open.c:929
do_open fs/namei.c:3683 [inline]
path_openat+0x284f/0x3270 fs/namei.c:3844
do_filp_open+0x1f2/0x430 fs/namei.c:3871
do_sys_openat2+0x134/0x1d0 fs/open.c:1422
do_sys_open fs/open.c:1437 [inline]
__do_sys_openat fs/open.c:1453 [inline]
__se_sys_openat fs/open.c:1448 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1448
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efd6115e98e
RSP: 002b:00007efd620f2b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007efd620f36c0 RCX: 00007efd6115e98e
RDX: 0000000000020600 RSI: 00007efd620f2c00 RDI: ffffffffffffff9c
RBP: 00007efd620f2c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007efd61426218 R14: 00007efd61426180 R15: 00007ffca2cbc228
Showing all locks held in the system:
1 lock held by khungtaskd/28:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6635
3 locks held by kworker/0:2/789:
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc90003aa7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc90003aa7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#2: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by getty/5535:
#0: ffff88802d2630a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
1 lock held by udevd/5771:
#0: ffff888021deb4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by syz-executor/5780:
2 locks held by kworker/0:6/5850:
#0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc90002e47d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc90002e47d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
1 lock held by syz.2.185/6613:
#0: ffff888021deb4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by syz.0.320/7250:
#0: ffff888021deb4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1077
5 locks held by syz-executor/7329:
#0: ffff88807730ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff88807730ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x500 net/bluetooth/hci_core.c:2709
#1: ffff88807730c0b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x552/0x1150 net/bluetooth/hci_sync.c:5396
#2: ffffffff8e53eb68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2016 [inline]
#2: ffffffff8e53eb68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0x99/0x220 net/bluetooth/hci_conn.c:2582
#3: ffff88802bd37b38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x7b/0x630 net/bluetooth/l2cap_core.c:1793
#4: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#4: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz.3.359/7453:
#0: ffff888021deb4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1077
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3433 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:__lock_acquire+0x461/0x7d80 kernel/locking/lockdep.c:5073
Code: 6b 18 4c 89 e8 48 c1 e8 03 48 89 84 24 b8 00 00 00 42 80 3c 00 00 74 12 4c 89 ef e8 d9 77 77 00 49 b8 00 00 00 00 00 fc ff df <48> 8b 45 10 49 89 45 00 65 8b 05 ac e6 99 7e 31 db 85 c0 0f 95 c3
RSP: 0018:ffffc9000c927620 EFLAGS: 00000046
RAX: 1ffff11005b0952f RBX: ffff88802d84a960 RCX: ffff88802d849e00
RDX: 0000000000000021 RSI: 0000000000000021 RDI: ffff88802d84a968
RBP: ffffc9000c927868 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d1862e R12: 0000000000000000
R13: ffff88802d84a978 R14: 0000000000000000 R15: ffff88802d84a8e8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5756
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:768 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:848 [inline]
batadv_iv_ogm_schedule+0x45c/0x1080 net/batman-adv/bat_iv_ogm.c:907
batadv_iv_send_outstanding_bat_ogm_packet+0x6ed/0x800 net/batman-adv/bat_iv_ogm.c:1804
process_one_work kernel/workqueue.c:2657 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293