INFO: task syz.1.1769:12022 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.1.1769 state:D stack:28584 pid:12022 tgid:12019 ppid:5622 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
bdev_open+0xde/0xd70 block/bdev.c:990
blkdev_open+0x461/0x600 block/fops.c:680
do_dentry_open+0x80e/0x1360 fs/open.c:1000
vfs_open_consume+0x4a/0x350 fs/open.c:1131
do_open fs/namei.c:4845 [inline]
path_openat+0x16fc/0x20f0 fs/namei.c:5010
do_file_open+0x23e/0x4a0 fs/namei.c:5039
do_sys_openat2+0x115/0x200 fs/open.c:1442
do_sys_open fs/open.c:1448 [inline]
__do_sys_openat fs/open.c:1464 [inline]
__se_sys_openat fs/open.c:1459 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1459
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f67a715fd8e
RSP: 002b:00007f67a8015b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f67a80166c0 RCX: 00007f67a715fd8e
RDX: 0000000000000082 RSI: 00007f67a8015c00 RDI: ffffffffffffff9c
RBP: 00007f67a8015c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f67a7426038 R14: 00007f67a7425fa0 R15: 00007ffcccc14658
Showing all locks held in the system:
locks held by khungtaskd/33: 1, last CPU#0:
#0: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5368: 2, on CPU#0:
#0: ffff888035e710a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000323b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/5614: 1, on CPU#0:
#0: ffff888027e05350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by udevd/5631: 1, on CPU#1:
#0: ffff888027e01350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by kworker/u8:19/6428: 4, last CPU#1:
#0: ffff88802d25c940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3431 [inline]
#0: ffff88802d25c940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0xea6/0x1630 kernel/workqueue.c:3479
#1: ffffc9000e39fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000e39fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000e39fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000e39fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff888029db69c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xd4/0xfc0 net/batman-adv/bat_iv_ogm.c:1010
#3: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:870 [inline]
#3: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:949 [inline]
#3: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule+0x41f/0xfc0 net/batman-adv/bat_iv_ogm.c:1011
locks held by udevd/6910: 1, on CPU#1:
#0: ffff88802761a350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by udevd/10854: 1, on CPU#1:
#0: ffff888027e7e350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz.1.1769/12022: 1, on CPU#0:
#0: ffff888027e05350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd2/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 6428 Comm: kworker/u8:19 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:mark_lock+0x22/0x190 kernel/locking/lockdep.c:4766
Code: 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 8b 46 20 89 c1 81 e1 00 00 03 00 48 83 f9 01 bb 09 00 00 00 83 db 00 <83> fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 25 ff 1f 00 00 48 0f
RSP: 0018:ffffc9000e39f760 EFLAGS: 00000002
RAX: d1000000000407c7 RBX: 0000000000000008 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffff88802d3e0c00 RDI: ffff88802d3e0000
RBP: 0000000000000018 R08: ffffffff917a7ebf R09: 1ffffffff22f4fd7
R10: dffffc0000000000 R11: fffffbfff22f4fd8 R12: ffff88802d3e0c28
R13: ffff888053ce7c20 R14: ffff88802d3e0c00 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff888123bb1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b7c5e327e0 CR3: 000000003384c000 CR4: 0000000000350ef0
Call Trace:
mark_held_locks kernel/locking/lockdep.c:4369 [inline]
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4395 [inline]
lockdep_hardirqs_on_prepare+0x17c/0x270 kernel/locking/lockdep.c:4454
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:210 [inline]
_raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:221
batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:671 [inline]
batadv_iv_ogm_queue_add+0xa67/0xd90 net/batman-adv/bat_iv_ogm.c:769
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:957 [inline]
batadv_iv_ogm_schedule+0x84b/0xfc0 net/batman-adv/bat_iv_ogm.c:1011
batadv_iv_send_outstanding_bat_ogm_packet+0x622/0x740 net/batman-adv/bat_iv_ogm.c:1924
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245