INFO: task syz.1.1301:10812 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1301 state:D stack:26824 pid:10812 tgid:10811 ppid:5809 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__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: 0033:0x7f3833b9c629
RSP: 002b:00007f3834a29028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f3833e15fa0 RCX: 00007f3833b9c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3833e15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3833e16038 R14: 00007f3833e15fa0 R15: 00007fff5ebe0b28
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5564:
#0: ffff8880395080a0 (&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/5795:
#0: ffff8880277d4358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
3 locks held by kworker/u8:10/5983:
#0: ffff888033c9b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc90004857d08 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffffffff9060f268 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff9060f268 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4198
3 locks held by kworker/u8:15/5993:
#0: ffff88813fe9c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc900049afd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffffffff9060f268 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
1 lock held by syz.1.1301/10812:
#0: ffff8880277d4358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
2 locks held by syz.0.1605/12249:
#0: ffff88803373e0e0 (&type->s_umount_key#77/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd20 fs/super.c:345
#1: ffff8880277d4358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:961
1 lock held by syz.8.1733/12767:
#0: ffffffff8e7f4ec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.8.1733/12778:
#0: ffffffff9060f268 (rtnl_mutex){+.+.}-{4:4}, at: wext_ioctl_dispatch.constprop.0+0xa3/0x3e0 net/wireless/wext-core.c:1013
2 locks held by syz.5.1734/12773:
#0: ffffffff9060f268 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff9060f268 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
#1: ffffffff8e7f4ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 0
CPU: 0 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 02/12/2026
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:467
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 58 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:mark_lock+0x90/0xa20 kernel/locking/lockdep.c:4774
Code: f1 48 23 48 60 0f 84 03 03 00 00 b8 01 00 00 00 48 8b 54 24 68 65 48 2b 15 75 c9 28 12 0f 85 ea 07 00 00 48 8d 65 d8 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 cc cc cc cc f6 46 22 03 74 8d 41 be 00 02
RSP: 0018:ffffc900015f79c8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88801d778b40 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffff88801d778b40 RDI: ffff88801d778000
RBP: ffffc900015f79e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: ffff88801d778000 R14: 0000000000000004 R15: 00000000000001af
FS: 0000000000000000(0000) GS:ffff88812444a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc336de6158 CR3: 000000007edcd000 CR4: 00000000003526f0
DR0: 0000000000000003 DR1: 00000000000001f8 DR2: 000000000000008e
DR3: 000000000000057a DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
mark_held_locks+0x40/0x70 kernel/locking/lockdep.c:4325
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline]
lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4410 [inline]
lockdep_hardirqs_on_prepare+0xb4/0x1b0 kernel/locking/lockdep.c:4362
trace_hardirqs_on+0x36/0x40 kernel/trace/trace_preemptirq.c:78
__local_bh_enable_ip+0x9e/0x120 kernel/softirq.c:455
spin_unlock_bh include/linux/spinlock.h:395 [inline]
batadv_tt_local_purge+0x21c/0x3d0 net/batman-adv/translation-table.c:1315
batadv_tt_purge+0x8b/0xbd0 net/batman-adv/translation-table.c:3509
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245