INFO: task syz.4.455:8426 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.455 state:D stack:26216 pid:8426 ppid:7539 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
sync_bdevs+0x1af/0x330 block/bdev.c:1059
ksys_sync+0xba/0x150 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff09f58ebe9
RSP: 002b:00007ff0a038f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007ff09f7c6090 RCX: 00007ff09f58ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ff09f7c6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff09f7c6128 R14: 00007ff09f7c6090 R15: 00007ffeffb210a8
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2fc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fc20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fc20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:7/1140:
1 lock held by udevd/5162:
2 locks held by getty/5553:
#0: ffff88814c8250a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by kworker/1:5/5890:
1 lock held by udevd/8013:
#0: ffff88814130e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
1 lock held by syz.4.455/8426:
#0: ffff88814130e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:mod_node_state+0x31/0x160 mm/vmstat.c:617
Code: 41 54 53 89 cd 41 89 d4 41 89 f7 49 89 fe 48 8d 9f c0 57 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 c5 17 1c 00 4c 8b 2b 44 89 fb 41 83 ff 2c 0f 83
RSP: 0018:ffffc90000117680 EFLAGS: 00000246
RAX: 1ffff11027fffef8 RBX: ffff88813ffff7c0 RCX: dffffc0000000000
RDX: 0000000000001000 RSI: 0000000000000006 RDI: ffff88813fffa000
RBP: 0000000000000000 R08: ffffffff8e4a912f R09: 1ffffffff1c95225
R10: dffffc0000000000 R11: fffffbfff1c95226 R12: 0000000000001000
R13: 0000000000000001 R14: ffff88813fffa000 R15: 0000000000000006
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a32e45f028 CR3: 0000000024666000 CR4: 00000000003506f0
Call Trace:
account_slab mm/slab.h:643 [inline]
allocate_slab mm/slub.c:2041 [inline]
new_slab+0x10d/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
kmem_cache_alloc_node+0x1ea/0x330 mm/slub.c:3530
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
__netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:714
__netdev_alloc_skb_ip_align include/linux/skbuff.h:3292 [inline]
netdev_alloc_skb_ip_align include/linux/skbuff.h:3302 [inline]
batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:557 [inline]
batadv_iv_ogm_queue_add+0x73e/0xcf0 net/batman-adv/bat_iv_ogm.c:669
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:848 [inline]
batadv_iv_ogm_schedule+0xab3/0xe90 net/batman-adv/bat_iv_ogm.c:867
batadv_iv_send_outstanding_bat_ogm_packet+0x731/0x840 net/batman-adv/bat_iv_ogm.c:1711
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
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