INFO: task kworker/u8:9:3823 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:21248 pid:3823 tgid:3823 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1498/0x5140 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2dc/0x710 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75d/0x1060 fs/fs-writeback.c:1813
writeback_sb_inodes+0x92e/0x1910 fs/fs-writeback.c:2041
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118
wb_writeback+0x459/0xad0 fs/fs-writeback.c:2229
wb_check_old_data_flush fs/fs-writeback.c:2333 [inline]
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0xaf3/0xf00 fs/fs-writeback.c:2414
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Showing all locks held in the system:
3 locks held by kworker/1:0/31:
#0: ffff88813fe55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90000a5fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000a5fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffff88803c1b4260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490
1 lock held by khungtaskd/38:
#0: ffffffff8dbc7740 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:302 [inline]
#0: ffffffff8dbc7740 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dbc7740 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:2/43:
#0: ffff88813fe69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90000b57bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000b57bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
4 locks held by kworker/u8:5/987:
#0: ffff88814d9d8138 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814d9d8138 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90004a57bc0 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004a57bc0 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffff888037e90110 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xef/0xf60 net/batman-adv/bat_iv_ogm.c:872
#3: ffff8880b89464f8 (&s->lock_key#58){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#3: ffff8880b89464f8 (&s->lock_key#58){+.+.}-{3:3}, at: ___slab_alloc+0x2ac/0x13d0 mm/slub.c:4576
8 locks held by kworker/u8:7/1544:
4 locks held by kworker/u8:9/3823:
#0: ffff8881416bc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff8881416bc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc9000e477bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000e477bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffff8880336d00d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff88805e56ed28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by dhcpcd/5454:
#0: ffff8880311ed518 (&ei->socket.wq.wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#0: ffff8880311ed518 (&ei->socket.wq.wait){+.+.}-{3:3}, at: remove_wait_queue+0x23/0x110 kernel/sched/wait.c:73
3 locks held by dhcpcd/5455:
2 locks held by getty/5550:
#0: ffff88814d93a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
4 locks held by kworker/1:4/5865:
#0: ffff888030650938 ((wq_completion)mld){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888030650938 ((wq_completion)mld){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90005197bc0 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90005197bc0 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffff888038f4e628 (&idev->mc_lock){+.+.}-{4:4}, at: mld_ifc_work+0x2d/0xe70 net/ipv6/mcast.c:2692
#3: ffff8880b89464f8 (&s->lock_key#58){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#3: ffff8880b89464f8 (&s->lock_key#58){+.+.}-{3:3}, at: ___slab_alloc+0x2ac/0x13d0 mm/slub.c:4576
6 locks held by kworker/u8:11/5933:
#0: ffff88801aad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88801aad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90005467bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90005467bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8ef35440 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670
#3: ffff888036f210d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888036f210d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff888036f210d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0 net/devlink/core.c:506
#4: ffff8880323a6300 (&devlink->lock_key#15){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff8880323a6300 (&devlink->lock_key#15){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff8880323a6300 (&devlink->lock_key#15){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0 net/devlink/core.c:506
#5: ffffffff8dbcd9b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
4 locks held by syz.4.29/6071:
1 lock held by syz-executor/6906:
#0: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
1 lock held by syz-executor/6952:
#0: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5027
2 locks held by syz-executor/6996:
#0: ffffffff8e6a1248 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:302 [inline]
#0: ffffffff8e6a1248 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e6a1248 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8ef43d78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
1 lock held by modprobe/7030:
=============================================
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 01/24/2026
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+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6071 Comm: syz.4.29 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x80 kernel/kcov.c:217
Code: 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 98 d5 63 10 65 8b 35 b9 d5 63 10 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 54 0b 00 00 <89> d7 09 f7 74 11 85 f6 75 39 85 d2 74 35 83 b9 14 16 00 00 00 74
RSP: 0018:ffffc90005867680 EFLAGS: 00000246
RAX: ffffffff834b9626 RBX: 0000000000000004 RCX: ffff888027c6bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888038769000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff110070ed200 R14: 0000000000000000 R15: 1ffff110070ed202
FS: 00007fbb293756c0(0000) GS:ffff8881265b1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff7f6f2bfe8 CR3: 000000005baee000 CR4: 00000000003526f0
Call Trace:
dtSplitRoot+0x7a6/0x16c0 fs/jfs/jfs_dtree.c:1981
dtSplitUp fs/jfs/jfs_dtree.c:993 [inline]
dtInsert+0xf19/0x5f10 fs/jfs/jfs_dtree.c:871
jfs_mkdir+0x783/0xb00 fs/jfs/namei.c:271
vfs_mkdir+0x40b/0x630 fs/namei.c:5205
do_mkdirat+0x281/0x520 fs/namei.c:5239
__do_sys_mkdirat fs/namei.c:5261 [inline]
__se_sys_mkdirat fs/namei.c:5259 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5259
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb2b139e57
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbb29374e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fbb29374ee0 RCX: 00007fbb2b139e57
RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000140 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000200000000140 R11: 0000000000000246 R12: 0000200000000040
R13: 00007fbb29374ea0 R14: 0000000000000000 R15: 0000000000000000