------------[ cut here ]------------
dst_release underflow
WARNING: CPU: 1 PID: 3535 at net/core/dst.c:175 dst_release+0xd8/0xe0 net/core/dst.c:175
Modules linked in:
CPU: 0 PID: 3535 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dst_release+0xd8/0xe0 net/core/dst.c:175
Code: 4c 89 f2 89 d9 31 c0 5b 41 5e 5d e9 ca d4 79 f9 e8 0d f2 93 f9 c6 05 68 80 3a 06 01 48 c7 c7 60 c0 54 8b 31 c0 e8 78 e8 5f f9 <0f> 0b eb 85 0f 1f 40 00 53 48 89 fb e8 e7 f1 93 f9 48 83 c3 a8 48
RSP: 0018:ffffc90019447680 EFLAGS: 00010246
RAX: 84924617b1dc8d00 RBX: 00000000ffffffff RCX: 0000000000040000
RDX: ffffc90002521000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 0000000000000000 R08: ffffffff8165eb92 R09: ffffed1017363f24
R10: ffffed1017363f24 R11: 0000000000000000 R12: 0000607f46289f68
R13: 1ffffffff1c7324d R14: ffff888093570640 R15: dffffc0000000000
FS:  00007ff6d1cfa700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000544038 CR3: 0000000061363000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dst_cache_destroy+0x107/0x1e0 net/core/dst_cache.c:160
 ipip6_dev_free net/ipv6/sit.c:1412 [inline]
 sit_init_net+0x229/0x550 net/ipv6/sit.c:1934
 ops_init+0x327/0x410 net/core/net_namespace.c:140
 setup_net+0x35b/0x9d0 net/core/net_namespace.c:333
 copy_net_ns+0x392/0x5e0 net/core/net_namespace.c:474
 create_new_namespaces+0x4ce/0xa00 kernel/nsproxy.c:110
 copy_namespaces+0x2f6/0x350 kernel/nsproxy.c:178
 copy_process+0x23a4/0x5b30 kernel/fork.c:2122
 kernel_clone+0x21a/0x7d0 kernel/fork.c:2509
 __do_sys_clone3 kernel/fork.c:2784 [inline]
 __se_sys_clone3+0x36b/0x410 kernel/fork.c:2768
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff6d1cfa188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020001440
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffe3129e35f R14: 00007ff6d1cfa300 R15: 0000000000022000