INFO: task syz.2.107:733 blocked for more than 124 seconds.
Not tainted 6.12.38-syzkaller-g78c6c49396da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.107 state:D stack:0 pid:733 tgid:733 ppid:293 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5945 [inline]
__schedule+0x1322/0x1df0 kernel/sched/core.c:7791
__schedule_loop kernel/sched/core.c:7872 [inline]
schedule+0xc6/0x240 kernel/sched/core.c:7887
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589
netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10868
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
tun_detach drivers/net/tun.c:704 [inline]
tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e0/0x250 kernel/task_work.c:240
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x9bc/0x2630 kernel/exit.c:953
do_group_exit+0x22a/0x300 kernel/exit.c:1095
get_signal+0x139d/0x14f0 kernel/signal.c:2933
arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f0cb4bc14a5
RSP: 002b:00007f0cb5ab1f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f0cb4db6090 RCX: 00007f0cb4bc14a5
RDX: 00007f0cb5ab1fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0cb4c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f0cb4db6128 R14: 00007f0cb4db6090 R15: 00007ffdda39f2d8
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.38-syzkaller-g78c6c49396da #0 ce4c5f9462df5e0b5dcad023e2a34ea92bcb2402
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xd8f/0xed0 kernel/hung_task.c:423
kthread+0x2ca/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1521 Comm: syz-executor Not tainted 6.12.38-syzkaller-g78c6c49396da #0 ce4c5f9462df5e0b5dcad023e2a34ea92bcb2402
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:stack_trace_consume_entry+0x53/0x2a0 kernel/stacktrace.c:86
Code: 03 0f b6 04 13 84 c0 0f 85 14 01 00 00 44 8b 57 10 4c 8d 4f 08 4d 89 cd 49 c1 ed 03 41 0f b6 44 15 00 84 c0 0f 85 2d 01 00 00 <45> 3b 11 73 3c 4c 8d 67 0c 4d 89 e7 49 c1 ef 03 41 0f b6 04 17 84
RSP: 0018:ffffc9000022fbb0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff92000045f9a RCX: 000000000022fc00
RDX: dffffc0000000000 RSI: ffffffff8586eac8 RDI: ffffc9000022fcc0
RBP: ffffc9000022fbf8 R08: ffffc9000022fcd0 R09: ffffc9000022fcc8
R10: 0000000000000027 R11: ffffffff81742a80 R12: ffff88810c384c00
R13: 1ffff92000045f99 R14: ffffffff81742a80 R15: ffffc9000022fc08
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ced9ae4c0 CR3: 000000010bee2000 CR4: 00000000003526b0
Call Trace:
arch_stack_walk+0x12d/0x170 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x4a/0x60 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2417 [inline]
slab_free mm/slub.c:4666 [inline]
kmem_cache_free+0x1c1/0x510 mm/slub.c:4773
kfree_skbmem net/core/skbuff.c:-1 [inline]
__kfree_skb+0x18f/0x210 net/core/skbuff.c:1203
sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1240
packet_rcv+0x180/0x1670 net/packet/af_packet.c:2276
dev_queue_xmit_nit+0xa40/0xae0 net/core/dev.c:2418
xmit_one net/core/dev.c:3655 [inline]
dev_hard_start_xmit+0x187/0x770 net/core/dev.c:3678
__dev_queue_xmit+0x19cc/0x3790 net/core/dev.c:4514
dev_queue_xmit include/linux/netdevice.h:3141 [inline]
br_dev_queue_push_xmit+0x553/0x6d0 net/bridge/br_forward.c:53
NF_HOOK include/linux/netfilter.h:317 [inline]
br_forward_finish net/bridge/br_forward.c:66 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
__br_forward+0x25c/0x390 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
br_flood+0x67e/0x730 net/bridge/br_forward.c:245
br_handle_frame_finish+0x12bb/0x1720 net/bridge/br_input.c:215
nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
__netif_receive_skb_core+0xf4b/0x3940 net/core/dev.c:5651
__netif_receive_skb_one_core net/core/dev.c:5755 [inline]
__netif_receive_skb net/core/dev.c:5870 [inline]
process_backlog+0x3e5/0xae0 net/core/dev.c:6206
__napi_poll+0xd0/0x610 net/core/dev.c:6857
napi_poll net/core/dev.c:6926 [inline]
net_rx_action+0x584/0xce0 net/core/dev.c:7048
handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xa6/0x100 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
addrconf_ifdown+0x608/0x1940 net/ipv6/addrconf.c:3956
addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1
notifier_call_chain+0x10b/0x2c0 kernel/notifier.c:93
raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:2067 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2105 [inline]
call_netdevice_notifiers net/core/dev.c:2119 [inline]
unregister_netdevice_many_notify+0xe32/0x1bd0 net/core/dev.c:11489
unregister_netdevice_many net/core/dev.c:11551 [inline]
unregister_netdevice_queue+0x339/0x380 net/core/dev.c:11425
unregister_netdevice include/linux/netdevice.h:3165 [inline]
__tun_detach+0xca1/0x1460 drivers/net/tun.c:685
tun_detach drivers/net/tun.c:701 [inline]
tun_chr_close+0x93/0x150 drivers/net/tun.c:3517
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e0/0x250 kernel/task_work.c:240
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x9bc/0x2630 kernel/exit.c:953
do_group_exit+0x22a/0x300 kernel/exit.c:1095
get_signal+0x139d/0x14f0 kernel/signal.c:2933
arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fd206590a23
Code: Unable to access opcode bytes at 0x7fd2065909f9.
RSP: 002b:00007ffd6d699d08 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 000000000000002c RBX: 00007fd2072e4620 RCX: 00007fd206590a23
RDX: 000000000000002c RSI: 00007fd2072e4670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd6d699d24 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fd2072e4670 R15: 0000000000000000
net_ratelimit: 65435 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:1d:f9:f7:c5:f9, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:1d:f9:f7:c5:f9, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:1d:f9:f7:c5:f9, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
net_ratelimit: 84327 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:1d:f9:f7:c5:f9, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:1d:f9:f7:c5:f9, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)