INFO: task kworker/u8:8:1113 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8 state:D stack:20864 pid:1113 tgid:1113 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
io_schedule+0x80/0xe0 kernel/sched/core.c:7835
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:375
jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75d/0x11a0 fs/fs-writeback.c:1825
writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2054
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2239
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0x41a/0xf60 fs/fs-writeback.c:2426
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.2.1781:17198 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1781 state:D stack:24576 pid:17198 tgid:17197 ppid:10867 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2845
sync_filesystem+0xa2/0x250 fs/sync.c:54
jfs_reconfigure+0xc6/0xa00 fs/jfs/super.c:370
reconfigure_super+0x227/0x8a0 fs/super.c:1080
do_remount fs/namespace.c:3391 [inline]
path_mount+0xdc5/0x10e0 fs/namespace.c:4151
do_mount fs/namespace.c:4172 [inline]
__do_sys_mount fs/namespace.c:4361 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4338
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43d069da8a
RSP: 002b:00007f43ce8f5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f43ce8f5ee0 RCX: 00007f43d069da8a
RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000
RBP: 0000200000000f40 R08: 00007f43ce8f5ee0 R09: 000000000184a438
R10: 000000000184a438 R11: 0000000000000246 R12: 0000200000000f00
R13: 00007f43ce8f5ea0 R14: 0000000000000000 R15: 0000200000000280
Showing all locks held in the system:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/u8:2/43:
2 locks held by kworker/u8:8/1113:
#0: ffff88801aac4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801aac4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc900057bfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc900057bfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
2 locks held by getty/5552:
#0: ffff888036ac50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz.2.1781/17198:
#0: ffff88803e8380d0 (&type->s_umount_key#68){++++}-{4:4}, at: do_remount fs/namespace.c:3388 [inline]
#0: ffff88803e8380d0 (&type->s_umount_key#68){++++}-{4:4}, at: path_mount+0xd7d/0x10e0 fs/namespace.c:4151
2 locks held by udevd/17281:
4 locks held by kworker/u8:20/17465:
3 locks held by kworker/u8:21/17468:
#0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc900139efc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc900139efc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffffffff8f14e4c0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
2 locks held by syz-executor/19140:
4 locks held by syz.4.2138/19240:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 17465 Comm: kworker/u8:20 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
RIP: 0010:lock_release+0xa1/0x3d0 kernel/locking/lockdep.c:5888
Code: 41 83 bf b4 0b 00 00 00 0f 85 f7 01 00 00 49 81 3e 00 64 12 93 0f 84 ea 01 00 00 9c 5b fa 48 c7 c7 57 d2 57 8d e8 df 74 83 09 <65> ff 05 b8 7d ae 10 c7 44 24 24 01 00 00 00 83 3d d9 15 ca 0d 00
RSP: 0018:ffffc90013a0f920 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000080000002
RDX: 0000000000000001 RSI: ffffffff8d57d257 RDI: ffffffff8ba67680
RBP: ffffc90013a0fa58 R08: ffff888058038bd7 R09: 1ffff1100b00717a
R10: dffffc0000000000 R11: ffffed100b00717b R12: 1ffff92002741f3d
R13: ffffffff8b26116a R14: ffff888058038b98 R15: ffff88802d659e80
FS: 0000000000000000(0000) GS:ffff888126336000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f6f4684000 CR3: 00000000651b0000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:194
raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:97 [inline]
rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x17a/0x400 kernel/locking/spinlock_rt.c:57
spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
__batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:173
batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245