INFO: task syz-executor:1318 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:0 pid:1318 tgid:1318 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6063 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7883
__schedule_loop kernel/sched/core.c:7960 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7975
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8032
__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
rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
setup_net+0x51c/0x9b0 net/core/net_namespace.c:378
copy_net_ns+0x4fc/0xa20 net/core/net_namespace.c:510
create_new_namespaces+0x390/0x6f0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x4f9/0x920 kernel/fork.c:3385
__do_sys_unshare kernel/fork.c:3471 [inline]
__se_sys_unshare kernel/fork.c:3469 [inline]
__x64_sys_unshare+0x3c/0x50 kernel/fork.c:3469
x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f072179f427
RSP: 002b:00007fff52acdbf8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f0721a25f40 RCX: 00007f072179f427
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f0721a267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fff52acde38 R15: 0000000000000000
INFO: task syz-executor:1326 blocked for more than 125 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:0 pid:1326 tgid:1326 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6063 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7883
__schedule_loop kernel/sched/core.c:7960 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7975
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8032
__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
rtnl_lock net/core/rtnetlink.c:79 [inline]
rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6676
netlink_rcv_skb+0x24d/0x4e0 net/netlink/af_netlink.c:2549
rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6697
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x8bf/0xa70 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x7d1/0xad0 net/netlink/af_netlink.c:1890
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
__sys_sendto+0x663/0x6e0 net/socket.c:2197
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__x64_sys_sendto+0xe9/0x100 net/socket.c:2200
x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2ff3d592d7
RSP: 002b:00007ffcf8b73090 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055558a718500 RCX: 00007f2ff3d592d7
RDX: 0000000000000028 RSI: 00007f2ff4b54670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffcf8b730f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f2ff4b54670 R15: 0000000000000000
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 2db523747cf1beec8353ecf3fbcf651dac8dc83d
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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:114
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:63
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
cpumask_backtrace+0x1f/0x30 lib/nmi_backtrace.c:127
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xe45/0xf90 kernel/hung_task.c:423
kthread+0x2c4/0x360 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 721 Comm: kworker/u8:43 Not tainted syzkaller #0 2db523747cf1beec8353ecf3fbcf651dac8dc83d
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:401
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 7b e7 61 fb cc
RSP: 0018:ffffc900000078d8 EFLAGS: 00000246
RAX: ffffffff8516fd08 RBX: ffff88817b3ea0e0 RCX: 0000000000000100
RDX: ffff888103bb1300 RSI: 0000000000000002 RDI: 000000000000ffff
RBP: ffffc90000007950 R08: ffff888103bb1300 R09: 0000000000000002
R10: 0000000000000000 R11: ffffffff8516fbf0 R12: 1ffff1102f67d417
R13: 1ffff1102f67d41c R14: 0000000000000002 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055589e529af8 CR3: 000000010b3f8000 CR4: 00000000003526b0
Call Trace:
__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+0xcd/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
__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+0x60d/0x1970 net/ipv6/addrconf.c:3950
addrconf_notify+0x17a/0xeb0 net/ipv6/addrconf.c:-1
notifier_call_chain+0x103/0x2b0 kernel/notifier.c:93
raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:2074 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2112 [inline]
call_netdevice_notifiers net/core/dev.c:2126 [inline]
unregister_netdevice_many_notify+0xde1/0x1be0 net/core/dev.c:11533
unregister_netdevice_many net/core/dev.c:11595 [inline]
default_device_exit_batch+0x845/0x8d0 net/core/dev.c:12166
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x741/0xc90 net/core/net_namespace.c:642
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f4/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c4/0x360 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244