INFO: task syz.3.838:8328 blocked for more than 154 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.838 state:D stack:28096 pid:8328 tgid:8327 ppid:5670 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
device_lock include/linux/device.h:1102 [inline]
usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
chrdev_open+0x4d9/0x600 fs/char_dev.c:411
do_dentry_open+0x816/0x1380 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4700 [inline]
path_openat+0x2e44/0x3830 fs/namei.c:4859
do_file_open+0x23e/0x4a0 fs/namei.c:4888
do_sys_openat2+0x115/0x200 fs/open.c:1395
do_sys_open fs/open.c:1401 [inline]
__do_sys_openat fs/open.c:1417 [inline]
__se_sys_openat fs/open.c:1412 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1412
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c9e35d68e
RSP: 002b:00007f3c9f2f8b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3c9f2f96c0 RCX: 00007f3c9e35d68e
RDX: 0000000000000402 RSI: 00007f3c9f2f8c00 RDI: ffffffffffffff9c
RBP: 00007f3c9f2f8c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f3c9e616038 R14: 00007f3c9e615fa0 R15: 00007f3c9e73fa48
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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: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: 5803 Comm: kworker/0:7 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:unwind_next_frame+0x17b/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: e8 03 48 89 04 24 42 0f b6 04 20 84 c0 0f 85 92 1c 00 00 4c 89 7c 24 10 4c 89 6c 24 50 0f b6 1b 48 8b 44 24 20 42 80 3c 20 00 <4d> 8d 7e 48 74 08 4c 89 ff e8 a7 9c bc 00 49 8b 2f 48 83 f3 01 48
RSP: 0018:ffffc90000006ca0 EFLAGS: 00000246
RAX: 1ffff92000000db2 RBX: 0000000000000000 RCX: 0000000080000101
RDX: 0000000000000000 RSI: ffffffff8c293c00 RDI: ffffffff8c293bc0
RBP: 1ffff92000000db0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000006d98 R11: ffffffff81b116c0 R12: dffffc0000000000
R13: ffffffff8176a21f R14: ffffc90000006d48 R15: 1ffff92000000da9
FS: 0000000000000000(0000) GS:ffff88812525d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ef10ff8 CR3: 000000000e746000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000001 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4610 [inline]
slab_alloc_node mm/slub.c:4939 [inline]
kmem_cache_alloc_noprof+0x2b8/0x650 mm/slub.c:4946
skb_ext_maybe_cow net/core/skbuff.c:7112 [inline]
skb_ext_add+0x1b6/0x8e0 net/core/skbuff.c:7187
nf_bridge_unshare net/bridge/br_netfilter_hooks.c:170 [inline]
br_nf_forward_ip+0xc3/0xa30 net/bridge/br_netfilter_hooks.c:686
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
br_handle_frame_finish+0x1175/0x1990 net/bridge/br_input.c:229
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6093
__netif_receive_skb_one_core net/core/dev.c:6204 [inline]
__netif_receive_skb net/core/dev.c:6319 [inline]
process_backlog+0x706/0x1860 net/core/dev.c:6670
__napi_poll+0xaa/0x330 net/core/dev.c:7729
napi_poll net/core/dev.c:7792 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7949
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:arch_try_cmpxchg128 arch/x86/include/asm/cmpxchg_64.h:83 [inline]
RIP: 0010:__update_freelist_fast mm/slub.c:652 [inline]
RIP: 0010:slab_update_freelist mm/slub.c:718 [inline]
RIP: 0010:__slab_free+0xbd/0x2c0 mm/slub.c:5623
Code: 44 24 04 74 45 85 c0 74 41 45 31 e4 41 f6 46 0a 20 74 66 48 8b 44 24 40 48 8b 54 24 48 48 89 de 48 8b 5c 24 30 48 8b 4c 24 38 48 0f c7 4e 20 48 89 f3 0f 84 e8 00 00 00 48 89 44 24 40 48 89
RSP: 0018:ffffc90004d8ec60 EFLAGS: 00000202
RAX: ffff88803c692e00 RBX: ffff88803c692d00 RCX: 000000080010000e
RDX: 000000080010000f RSI: ffffea0000f1a480 RDI: ffff88801f691dc0
RBP: ffffc90004d8ecf0 R08: 0000000000000000 R09: ffffffff823351ae
R10: dffffc0000000000 R11: fffffbfff206311f R12: 0000000000000000
R13: ffff88803c692e00 R14: ffff88801f691dc0 R15: 0000000000000000
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4610 [inline]
slab_alloc_node mm/slub.c:4939 [inline]
__kmalloc_cache_noprof+0x2b6/0x660 mm/slub.c:5446
_kmalloc_noprof include/linux/slab.h:969 [inline]
add_stack_record_to_list mm/page_owner.c:184 [inline]
inc_stack_record_count mm/page_owner.c:226 [inline]
__set_page_owner+0x286/0x4c0 mm/page_owner.c:345
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x24ae/0x2530 mm/page_alloc.c:3941
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
alloc_slab_page mm/slub.c:3289 [inline]
allocate_slab+0x74/0x5d0 mm/slub.c:3404
new_slab mm/slub.c:3447 [inline]
refill_objects+0x328/0x3c0 mm/slub.c:7241
refill_sheaf mm/slub.c:2827 [inline]
__pcs_replace_empty_main+0x2e0/0x6b0 mm/slub.c:4692
alloc_from_pcs mm/slub.c:4790 [inline]
slab_alloc_node mm/slub.c:4924 [inline]
kmem_cache_alloc_noprof+0x373/0x650 mm/slub.c:4946
skb_clone+0x212/0x3a0 net/core/skbuff.c:2110
do_one_broadcast net/netlink/af_netlink.c:1456 [inline]
netlink_broadcast_filtered+0x578/0xea0 net/netlink/af_netlink.c:1539
netlink_broadcast+0x37/0x50 net/netlink/af_netlink.c:1563
uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline]
kobject_uevent_net_broadcast+0x378/0x560 lib/kobject_uevent.c:410
kobject_uevent_env+0x566/0x9e0 lib/kobject_uevent.c:611
__device_release_driver drivers/base/dd.c:1361 [inline]
device_release_driver_internal+0x782/0x880 drivers/base/dd.c:1372
bus_remove_device+0x444/0x560 drivers/base/bus.c:664
device_del+0x524/0x8f0 drivers/base/core.c:3961
usb_disconnect+0x630/0x9a0 drivers/usb/core/hub.c:2376
hub_port_connect drivers/usb/core/hub.c:5407 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
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
net_ratelimit: 5832 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)