INFO: task kworker/u8:14:526 blocked for more than 124 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:14 state:D stack:0 pid:526 tgid:526 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:6052 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7865
__schedule_loop kernel/sched/core.c:7942 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7957
schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x368/0x650 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x45a/0x580 kernel/rcu/tree.c:4657
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
cleanup_net+0x645/0xc90 net/core/net_namespace.c:638
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c7/0x360 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
INFO: task syz.0.777:3034 blocked for more than 125 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.777 state:D stack:0 pid:3034 tgid:3034 ppid:295 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:6052 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7865
__schedule_loop kernel/sched/core.c:7942 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7957
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8014
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rcu_barrier+0x4d/0x580 kernel/rcu/tree.c:4589
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
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:3520
__fput+0x208/0xa30 fs/file_table.c:447
____fput+0x20/0x30 fs/file_table.c:475
task_work_run+0x1e8/0x260 kernel/task_work.c:246
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0xa46/0x2850 kernel/exit.c:955
do_group_exit+0x21f/0x2f0 kernel/exit.c:1098
get_signal+0x134c/0x1490 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x700 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+0x57/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: eccb:0xe4a421182f13d611
RSP: 002b:00007f49c6cd6f58 EFLAGS: 00000756 ORIG_RAX: d1d66dbfed01019b
RAX: 2bf9e1987c4f44ee RBX: 6f67a894836fe1f3 RCX: ed0b474b2b46640f
RDX: fb381f0b5e12d2ce RSI: 401aaa756d8c34aa RDI: 30b9ec15aecde911
RBP: 532828f82bbb556c R08: dbce39d105fdbf88 R09: ae9ea378b9c9fbc7
R10: 33740f3b8630618c R11: 2450ade207355af5 R12: 0a61688f027fb1a4
R13: 339c71c774e61334 R14: 28baed4a0483d193 R15: 7c1f9cf2b758efdc
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 e549a79720f8b9d2445064a5e8a439d230f1aa2c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/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+0xe45/0xf90 kernel/hung_task.c:423
kthread+0x2c7/0x360 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: 33 Comm: rcuop/1 Not tainted syzkaller #0 e549a79720f8b9d2445064a5e8a439d230f1aa2c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__skb_dst_copy include/net/dst.h:283 [inline]
RIP: 0010:skb_dst_copy include/net/dst.h:290 [inline]
RIP: 0010:__copy_skb_header+0x13b/0x4e0 net/core/skbuff.c:1529
Code: 00 4d 85 ff ba 00 00 80 00 0f 44 d1 25 ff ff 7f ff 09 d0 41 89 86 81 00 00 00 4d 8d 66 58 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 e7 e8 6b 3b 66 fd 4d 85 ff 41 0f 95 c5 4d 89 3c 24 4c
RSP: 0018:ffffc900002305c8 EFLAGS: 00000246
RAX: 1ffff1102c0feb73 RBX: ffff888160701280 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881607f5bc1
RBP: ffffc900002305f0 R08: ffff88813012c000 R09: 0000000001000000
R10: ffff88813012c000 R11: 0000000001000000 R12: ffff8881607f5b98
R13: dffffc0000000000 R14: ffff8881607f5b40 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f24db945000 CR3: 000000010c7e8000 CR4: 00000000003526b0
Call Trace:
__skb_clone+0x5f/0x6d0 net/core/skbuff.c:1580
skb_clone+0x255/0x470 net/core/skbuff.c:2086
deliver_clone net/bridge/br_forward.c:125 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x4df/0x720 net/bridge/br_forward.c:237
br_handle_frame_finish+0x1157/0x1620 net/bridge/br_input.c:215
nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
br_handle_frame+0x5a5/0xba0 net/bridge/br_input.c:424
__netif_receive_skb_core+0xfc4/0x3a70 net/core/dev.c:5695
__netif_receive_skb_one_core net/core/dev.c:5799 [inline]
__netif_receive_skb net/core/dev.c:5914 [inline]
process_backlog+0x40b/0xaf0 net/core/dev.c:6250
__napi_poll+0xd0/0x600 net/core/dev.c:6901
napi_poll net/core/dev.c:6970 [inline]
net_rx_action+0x5dc/0xd70 net/core/dev.c:7092
handle_softirqs+0x1aa/0x620 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xb8/0x110 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_do_batch+0x590/0xcb0 kernel/rcu/tree.c:2594
nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
rcu_nocb_cb_kthread+0x533/0xb60 kernel/rcu/tree_nocb.h:957
kthread+0x2c7/0x360 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
net_ratelimit: 99031 callbacks suppressed
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 veth0_to_bridge with own address as source address (addr:8a:71:6a:1d:2d:33, 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 veth0_to_bridge with own address as source address (addr:8a:71:6a:1d:2d:33, 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: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)
net_ratelimit: 130245 callbacks suppressed
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 veth0_to_bridge with own address as source address (addr:8a:71:6a:1d:2d:33, 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 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:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8a:71:6a:1d:2d:33, 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 veth0_to_bridge with own address as source address (addr:8a:71:6a:1d:2d:33, vlan:0)