INFO: task syz.1.2571:14547 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2571 state:D stack:27632 pid:14547 tgid:14542 ppid:13872 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1709/0x5530 kernel/sched/core.c:7231
__schedule_loop kernel/sched/core.c:7308 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7323
cgroup_lock_and_drain_offline+0x51a/0x650 kernel/cgroup/cgroup.c:3275
cgroup1_get_tree+0x9d/0x890 kernel/cgroup/cgroup-v1.c:1265
vfs_get_tree+0x92/0x2a0 fs/super.c:1941
fc_mount fs/namespace.c:1198 [inline]
do_new_mount_fc fs/namespace.c:3777 [inline]
do_new_mount+0x319/0xdc0 fs/namespace.c:3853
do_mount fs/namespace.c:4186 [inline]
__do_sys_mount fs/namespace.c:4402 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4379
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ea8d2e0d9
RSP: 002b:00007f5ea6f44028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5ea8fb6180 RCX: 00007f5ea8d2e0d9
RDX: 0000200000000040 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f5ea8dc5024 R08: 0000200000000080 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5ea8fb6218 R14: 00007f5ea8fb6180 R15: 00007ffcf66dab98
Showing all locks held in the system:
locks held by khungtaskd/39: 1, last CPU#1:
#0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6835
locks held by kworker/0:2/205: 6, last CPU#0:
#0: ffff88801eac6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff88801eac6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff88801eac6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90004167c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90004167c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90004167c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffff88802acce210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802acce210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899
#3: ffff88806462e210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff88806462e210 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xe3/0x990 drivers/usb/core/hub.c:2336
#4: ffff8880384db1d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/[ 944.043466][ T39] #4: ffff8880384db1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff8880384db1d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/[ 944.043466][ T39] #4: ffff8880384db1d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff8880384db1d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/[ 944.043466][ T39] #4: ffff8880384db1d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
#5: ffffffff8e3c9a70 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
locks held by kworker/u8:14/1473: 5, on CPU#0:
#0: ffff88801bee0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff88801bee0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff88801bee0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90006f57c60 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90006f57c60 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90006f57c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8f7b5760 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
#3: ffffffff8f7c4a78 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0x9a0 net/core/dev.c:13225
#4: ffff88801aeaf238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_find_and_get_ns+0x34/0xe0 fs/kernfs/dir.c:968
locks held by kworker/u8:15/1498: 4, last CPU#0:
#0: ffff88801aea2938 ((wq_completion)kvfree_rcu_reclaim){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff88801aea2938 ((wq_completion)kvfree_rcu_reclaim){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff88801aea2938 ((wq_completion)kvfree_rcu_reclaim){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc900070f7c60 ((work_completion)(&(&krcp->krw_arr[i].rcu_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc900070f7c60 ((work_completion)(&(&krcp->krw_arr[i].rcu_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc900070f7c60 ((work_completion)(&(&krcp->krw_arr[i].rcu_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8e3c39a0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e3c39a0 (rcu_callback){....}-{0:0}, at: kvfree_rcu_bulk+0x6d/0x190 mm/slab_common.c:1496
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by udevd/5759: 4, on CPU#0:
#0: ffff888036b062c0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa5/0xcb0 fs/seq_file.c:183
#1: ffff888073e2d878 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
#2: ffff88807ec6c3c8 (kn->active#24){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88807ec6c3c8 (kn->active#24){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
#3: ffff88806462e210 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline]
#3: ffff88806462e210 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by kworker/0:8/7757: 3, on CPU#0:
#0: ffff88801eac6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff88801eac6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff88801eac6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90006427c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90006427c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90006427c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffff88802ac0e210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802ac0e210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899
locks held by kworker/u8:24/10785: 5, last CPU#0:
#0: ffff8880333b1938 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff8880333b1938 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff8880333b1938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc9000604fc60 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc9000604fc60 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc9000604fc60 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8e259320 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#4: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#4: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#4: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
locks held by kworker/u8:34/10795: 3, on CPU#0:
#0: ffff888033229138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff888033229138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff888033229138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90005f3fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90005f3fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90005f3fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8f7c4a78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#2: ffffffff8f7c4a78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4229
locks held by getty/13729: 2, on CPU#0:
#0: ffff888036c970a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000388b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/15441: 1, on CPU#0:
#0: ffffffff8f7c4a78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f7c4a78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#0: ffffffff8f7c4a78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4194
locks held by syz.4.2931/15841: 1, last CPU#1:
#0: ffff88801aeaf348 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3f/0x140 fs/kernfs/dir.c:1791
locks held by dhcpcd-run-hook/15862: 4, last CPU#0:
#0: ffff888067d27088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
#2: ffff88803fb0da18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffff88803fb0da18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1498 Comm: kworker/u8:15 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: kvfree_rcu_reclaim kfree_rcu_work
RIP: 0010:check_preemption_disabled+0x0/0xe0 lib/smp_processor_id.c:13
Code: c7 20 d0 cb 8b 48 c7 c6 60 d0 cb 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 53 65 8b 05 d7 9e 72 07 65 8b 0d cc 9e 72 07 f7 c1
RSP: 0000:ffffc900070f78a8 EFLAGS: 00000046
RAX: 1be71b14e22bbae7 RBX: 0000000000000002 RCX: 0000000000000000
RDX: ffff888027244c10 RSI: ffffffff8dbfaa0e RDI: ffffffff8bcbd080
RBP: ffff88802544abd0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000e1ef14 R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff99f7df90 R15: ffff888025449f40
FS: 0000000000000000(0000) GS:ffff8881259f2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff2e3f5ff8 CR3: 0000000069866000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_release+0x263/0x3c0 kernel/locking/lockdep.c:5930
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:198
__debug_check_no_obj_freed lib/debugobjects.c:1180 [inline]
debug_check_no_obj_freed+0x39e/0x450 lib/debugobjects.c:1201
slab_free_hook mm/slub.c:2637 [inline]
slab_free_freelist_hook mm/slub.c:2735 [inline]
slab_free_bulk mm/slub.c:6422 [inline]
kmem_cache_free_bulk+0x520/0x10e0 mm/slub.c:7159
kfree_bulk include/linux/slab.h:891 [inline]
kvfree_rcu_bulk+0xc6/0x190 mm/slab_common.c:1502
kfree_rcu_work+0xe8/0x160 mm/slab_common.c:1580
process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379
process_scheduled_works kernel/workqueue.c:3462 [inline]
worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543
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