------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 7027 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 7027 Comm: syz.3.669 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Code: 09 01 48 c7 c7 a0 d2 be 8a e8 ad 30 45 fd 0f 0b eb e0 e8 f4 1d 79 fd c6 05 fa 72 e2 09 01 48 c7 c7 e0 d1 be 8a e8 91 30 45 fd <0f> 0b eb c4 e8 d8 1d 79 fd c6 05 df 72 e2 09 01 48 c7 c7 40 d2 be
RSP: 0018:ffffc90000007748 EFLAGS: 00010246
RAX: 6afc4dd395690300 RBX: 0000000000000002 RCX: ffff88804f4d9dc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000078a8 R08: dffffc0000000000 R09: fffff52000000e79
R10: fffff52000000e79 R11: 1ffff92000000e78 R12: ffff888076d89c40
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88807292a448
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab844e5000 CR3: 000000007e7c3000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 get_net include/net/net_namespace.h:257 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
 tipc_crypto_xmit+0x17a9/0x2300 net/tipc/crypto.c:1761
 tipc_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1656
 tipc_crypto_xmit+0x1928/0x2300 net/tipc/crypto.c:1717
 tipc_bearer_xmit_skb+0x242/0x3f0 net/tipc/bearer.c:574
 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 do_softirq+0x13b/0x200 kernel/softirq.c:497
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x174/0x1b0 kernel/softirq.c:421
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __fib6_clean_all+0x239/0x370 net/ipv6/ip6_fib.c:2262
 rt6_sync_down_dev net/ipv6/route.c:4944 [inline]
 rt6_disable_ip+0x120/0x7f0 net/ipv6/route.c:4949
 addrconf_ifdown+0x162/0x1a10 net/ipv6/addrconf.c:3804
 addrconf_notify+0x405/0xf40 net/ipv6/addrconf.c:-1
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 dev_close_many+0x28d/0x400 net/core/dev.c:1601
 unregister_netdevice_many+0x471/0x1840 net/core/dev.c:10952
 unregister_netdevice_queue+0x31c/0x360 net/core/dev.c:10909
 unregister_netdevice include/linux/netdevice.h:3075 [inline]
 __tun_detach+0xd4a/0x1500 drivers/net/tun.c:685
 tun_detach drivers/net/tun.c:701 [inline]
 tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3492
 __fput+0x22c/0x920 fs/file_table.c:320
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0x936/0x2400 kernel/exit.c:871
 do_group_exit+0x217/0x2d0 kernel/exit.c:1021
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc4feb8e929
Code: Unable to access opcode bytes at 0x7fc4feb8e8ff.
RSP: 002b:00007fc4ff9a4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 00000000000002e9 RBX: 00007fc4fedb5fa0 RCX: 00007fc4feb8e929
RDX: 00000000000002e9 RSI: 0000200000000480 RDI: 0000000000000005
RBP: 00007fc4fec10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc4fedb5fa0 R15: 00007fff9741c128
 </TASK>