INFO: task syz-executor:10150 blocked for more than 122 seconds.
      Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10150 tgid:10150 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 ppp_exit_net+0x116/0x340 drivers/net/ppp/ppp_generic.c:1157
 ops_exit_list net/core/net_namespace.c:173 [inline]
 setup_net+0x66c/0x990 net/core/net_namespace.c:388
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3351
 __do_sys_unshare kernel/fork.c:3422 [inline]
 __se_sys_unshare kernel/fork.c:3420 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3420
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f826b190127
RSP: 002b:00007ffef1532d48 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f826b3b5f40 RCX: 00007f826b190127
RDX: 0000000000000005 RSI: 00007ffef1532c10 RDI: 0000000040000000
RBP: 00007f826b3b6738 R08: 00007f826bee7d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:10166 blocked for more than 123 seconds.
      Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10166 tgid:10166 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 ip_tunnel_init_net+0x2f2/0x860 net/ipv4/ip_tunnel.c:1159
 vti_init_net+0x33/0x140 net/ipv4/ip_vti.c:517
 ops_init+0x1af/0x5d0 net/core/net_namespace.c:139
 setup_net+0x20e/0x990 net/core/net_namespace.c:356
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3351
 __do_sys_unshare kernel/fork.c:3422 [inline]
 __se_sys_unshare kernel/fork.c:3420 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3420
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fcc12190127
RSP: 002b:00007ffcb503b0e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fcc123b5f40 RCX: 00007fcc12190127
RDX: 0000000000000005 RSI: 00007ffcb503afb0 RDI: 0000000040000000
RBP: 00007fcc123b6738 R08: 00007fcc12ee7d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:10167 blocked for more than 124 seconds.
      Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10167 tgid:10167 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 ip_tunnel_init_net+0x2f2/0x860 net/ipv4/ip_tunnel.c:1159
 erspan_init_net+0x2d/0x40 net/ipv4/ip_gre.c:1756
 ops_init+0x1af/0x5d0 net/core/net_namespace.c:139
 setup_net+0x20e/0x990 net/core/net_namespace.c:356
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3351
 __do_sys_unshare kernel/fork.c:3422 [inline]
 __se_sys_unshare kernel/fork.c:3420 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3420
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f789f390127
RSP: 002b:00007ffc98daa6f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f789f5b5f40 RCX: 00007f789f390127
RDX: 0000000000000005 RSI: 00007ffc98daa5c0 RDI: 0000000040000000
RBP: 00007f789f5b6738 R08: 00007f78a00e7d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 f1acc3ef52b3e732a05c4f7a2560722db90bb473
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __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:229 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:385
 kthread+0x2c7/0x370 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 553 Comm: kworker/u8:8 Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 f1acc3ef52b3e732a05c4f7a2560722db90bb473
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
RIP: 0010:br_multicast_rcv+0x492/0x7af0 net/bridge/br_multicast.c:3972
Code: 83 fc 08 74 7b 41 81 fc 86 dd 00 00 0f 85 d9 00 00 00 43 80 3c 3e 00 74 08 4c 89 ef e8 17 9d df fc 4d 8b 65 00 4c 8b 6c 24 28 <4c> 89 e8 48 c1 e8 03 42 80 3c 38 00 4c 8b 74 24 18 74 08 4c 89 ef
RSP: 0018:ffffc90000230100 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 1ffff1102873968e RCX: 0000000000000003
RDX: ffffffff84fbca97 RSI: ffffffff87b4c020 RDI: 000000000000dd86
RBP: ffffc90000230750 R08: ffff888119232600 R09: 0000000000000002
R10: 000000000000dd86 R11: 0000000000000100 R12: ffff88810b7a4bf8
R13: ffffc90000230800 R14: 1ffff92000046104 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556096728b98 CR3: 000000010b36c000 CR4: 00000000003526b0
DR0: 0000000000000007 DR1: 000000000000000b DR2: 0000000000000004
DR3: 0000000000000002 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 br_handle_frame_finish+0x5be/0x1720 net/bridge/br_input.c:153
 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+0xf48/0x3940 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:6202
 __napi_poll+0xd0/0x610 net/core/dev.c:6853
 napi_poll net/core/dev.c:6922 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7044
 handle_softirqs+0x1ab/0x630 kernel/softirq.c:603
 __do_softirq+0xf/0x16 kernel/softirq.c:641
 do_softirq+0xa6/0x100 kernel/softirq.c:485
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412
 __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]
 __fib6_clean_all+0x35e/0x410 net/ipv6/ip6_fib.c:2277
 fib6_clean_all+0x2e/0x50 net/ipv6/ip6_fib.c:2286
 rt6_sync_down_dev net/ipv6/route.c:4927 [inline]
 rt6_disable_ip+0x129/0x870 net/ipv6/route.c:4932
 addrconf_ifdown+0x161/0x1940 net/ipv6/addrconf.c:3899
 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:11485
 unregister_netdevice_many net/core/dev.c:11547 [inline]
 default_device_exit_batch+0x810/0x8a0 net/core/dev.c:12030
 ops_exit_list net/core/net_namespace.c:178 [inline]
 cleanup_net+0x72e/0xc70 net/core/net_namespace.c:642
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d2/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
 kthread+0x2c7/0x370 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
 </TASK>