INFO: task kworker/u8:6:1176 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:20168 pid:1176 tgid:1176 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:6)
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
io_schedule+0x81/0xe0 kernel/sched/core.c:7871
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x26e/0xb10 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:1564 [inline]
__writeback_single_inode+0x6f4/0x1000 fs/fs-writeback.c:1784
writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:2015
wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195
wb_do_writeback fs/fs-writeback.c:2342 [inline]
wb_workfn+0x40e/0xf00 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.6.576:8897 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.576 state:D stack:25264 pid:8897 tgid:8896 ppid:7636 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
__writeback_inodes_sb_nr+0x1f7/0x270 fs/fs-writeback.c:2787
sync_filesystem+0xa2/0x250 fs/sync.c:54
jfs_reconfigure+0xc6/0xa00 fs/jfs/super.c:370
reconfigure_super+0x227/0x890 fs/super.c:1076
do_remount fs/namespace.c:3270 [inline]
path_mount+0xd1a/0xfe0 fs/namespace.c:4020
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4206
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe74f8d0e6a
RSP: 002b:00007fe74db2de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe74db2def0 RCX: 00007fe74f8d0e6a
RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000
RBP: 0000200000000f40 R08: 00007fe74db2def0 R09: 0000000001a4a438
R10: 0000000001a4a438 R11: 0000000000000246 R12: 0000200000000f00
R13: 00007fe74db2deb0 R14: 0000000000000000 R15: 0000200000000100
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/1158:
#0: ffff888147eac938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888147eac938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004d6fba0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004d6fba0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by kworker/u8:6/1176:
#0: ffff8881412e1938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff8881412e1938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004e0fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004e0fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
7 locks held by kworker/u8:8/1441:
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000539fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000539fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e8568e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669
#3: ffff88803afa80d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88803afa80d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff88803afa80d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506
#4: ffff88803afab300 (&devlink->lock_key#26){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff88803afab300 (&devlink->lock_key#26){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff88803afab300 (&devlink->lock_key#26){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506
#5: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1173
#6: ffff888023c4ce98 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2765 [inline]
#6: ffff888023c4ce98 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x564/0x2380 net/core/dev.c:12244
4 locks held by kworker/u8:10/1528:
3 locks held by kworker/u8:13/5040:
#0: ffff88814d10d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88814d10d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90010e0fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90010e0fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194
2 locks held by getty/5559:
#0: ffff88823bf2c0a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz.6.576/8897:
#0: ffff8880240780d0 (&type->s_umount_key#95){++++}-{4:4}, at: do_remount fs/namespace.c:3267 [inline]
#0: ffff8880240780d0 (&type->s_umount_key#95){++++}-{4:4}, at: path_mount+0xcd4/0xfe0 fs/namespace.c:4020
1 lock held by syz.9.610/9140:
#0: ffff8880240780d0 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880240780d0 (&type->s_umount_key#95){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
7 locks held by syz-executor/10510:
#0: ffff8880349ec480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3113 [inline]
#0: ffff8880349ec480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88806c43dc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88814533fc38 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88814533fc38 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e0f4478 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
#4: ffff88806d15b0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88806d15b0d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#5: ffff888048eaf300 (&devlink->lock_key#29){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582
#6: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1047 [inline]
#6: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x800/0x1060 drivers/net/netdevsim/netdev.c:1141
1 lock held by syz.8.720/10603:
#0: ffff8880240780d0 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880240780d0 (&type->s_umount_key#95){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz-executor/10647:
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
1 lock held by syz-executor/10687:
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
1 lock held by syz-executor/10699:
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
2 locks held by syz-executor/10727:
#0: ffffffff8ed816e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ed816e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8ed816e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e8637f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
4 locks held by dhcpcd-run-hook/10866:
=============================================
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 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 1528 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_dat_purge
RIP: 0010:__lock_acquire+0x2d/0xd20 kernel/locking/lockdep.c:5093
Code: 41 56 41 55 41 54 53 48 83 ec 30 48 89 fb 65 48 8b 3c 25 08 90 a2 91 45 31 ff 83 3d dc 6f 3a 0d 00 0f 84 7e 0c 00 00 48 8b 03 <48> 3d 20 33 66 92 0f 84 6f 0c 00 00 41 89 cc 41 89 d6 8b 0d fb c7
RSP: 0018:ffffc90005abf7f0 EFLAGS: 00000002
RAX: ffffffff990c5e00 RBX: ffff88804f4961d8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802785bc00
RBP: ffffffff8a8c4b21 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1dac80f R12: 0000000000000000
R13: ffff88804f4961d8 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126df7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f233af98286 CR3: 000000007cf40000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
spin_lock_bh include/linux/spinlock_rt.h:88 [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:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245