INFO: task kworker/u8:9:1636 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:21064 pid:1636 tgid:1636 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1681/0x54c0 kernel/sched/core.c:7183
__schedule_loop kernel/sched/core.c:7262 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7277
io_schedule+0x80/0xe0 kernel/sched/core.c:8104
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/0x10e0 fs/fs-writeback.c:1825
writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2054
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2239
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2426
process_one_work kernel/workqueue.c:3288 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452
kthread+0x388/0x470 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
INFO: task syz-executor:12930 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22360 pid:12930 tgid:12930 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1681/0x54c0 kernel/sched/core.c:7183
__schedule_loop kernel/sched/core.c:7262 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7277
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
generic_shutdown_super+0x77/0x2d0 fs/super.c:625
kill_block_super+0x44/0x90 fs/super.c:1725
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f450fb1da57
RSP: 002b:00007ffdbf6374c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f450fbb2048 RCX: 00007f450fb1da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdbf637580
RBP: 00007ffdbf637580 R08: 00007ffdbf638580 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdbf638610
R13: 00007f450fbb2048 R14: 00000000000feb2b R15: 00007ffdbf638650
Showing all locks held in the system:
4 locks held by rcuc/0/20:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:7/1012:
2 locks held by kworker/u8:9/1636:
#0: ffff88801b285938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801b285938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
#1: ffffc900065cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc900065cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
2 locks held by kworker/u8:12/2984:
2 locks held by getty/5552:
#0: ffff88803766f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
4 locks held by kworker/u8:15/6549:
#0: ffff88801b6a9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801b6a9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
#1: ffffc90003997c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc90003997c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
#2: ffffffff8f34ac60 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffff88807c2a5838 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249
3 locks held by kworker/u8:16/6564:
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
#1: ffffc90003ac7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc90003ac7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
#2: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by syz-executor/12930:
#0: ffff888029f2c0d0 (&type->s_umount_key#83){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888029f2c0d0 (&type->s_umount_key#83){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888029f2c0d0 (&type->s_umount_key#83){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
2 locks held by kworker/u8:4/13256:
2 locks held by udevd/13275:
3 locks held by udevd/14036:
14 locks held by syz-executor/14344:
1 lock held by syz-executor/14442:
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f359578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
1 lock held by syz.7.1087/14662:
1 lock held by syz.3.1089/14680:
2 locks held by syz.1.1090/14682:
3 locks held by dhcpcd-run-hook/14683:
=============================================
NMI backtrace for cpu 0
CPU: 0 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+0xfaa/0x1000 kernel/hung_task.c:515
kthread+0x388/0x470 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: 2984 Comm: kworker/u8:12 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:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:752
Code: e8 eb 6d 7e 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 90 37 8c 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 ac 68 82 00 48 c7 c3 58 ee 70 92 49 03 1e 48 89
RSP: 0018:ffffc9000d7af8e0 EFLAGS: 00000246
RAX: 1ffffffff1b186f3 RBX: 0000000000000001 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8ba684e0 RDI: ffffffff8ba684a0
RBP: ffffffff8b2a09f0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f15297 R12: 0000000000000002
R13: ffffffff8dfc8400 R14: ffffffff8d8c3798 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126225000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd1ff2f000 CR3: 0000000060fe0000 CR4: 00000000003526f0
Call Trace:
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
rt_spin_lock+0x1fc/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:3288 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452
kthread+0x388/0x470 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