------------[ cut here ]------------
dst_release underflow
WARNING: CPU: 1 PID: 21014 at net/core/dst.c:173 dst_release net/core/dst.c:173 [inline]
WARNING: CPU: 1 PID: 21014 at net/core/dst.c:173 dst_release+0xd2/0xe0 net/core/dst.c:167
Modules linked in:
CPU: 1 PID: 21014 Comm: syz-executor.1 Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dst_release net/core/dst.c:173 [inline]
RIP: 0010:dst_release+0xd2/0xe0 net/core/dst.c:167
Code: 89 c3 89 c6 e8 2f 70 54 fa 85 db 74 a4 e9 88 f5 0e 02 e8 e1 68 54 fa 48 c7 c7 c0 2c 8c 8a c6 05 c9 8f 37 06 01 e8 6a 22 d1 01 <0f> 0b eb c6 66 2e 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 48
RSP: 0018:ffffc900178f7bd0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815e88a8 RDI: fffff52002f1ef6c
RBP: ffffe8ffffc84bc8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815e264e R11: 0000000000000000 R12: ffff88804404d480
R13: 00000000ffffffff R14: 0000000000000007 R15: 0000000000000000
FS:  00007f8f51fba700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd2c000 CR3: 000000007766c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dst_cache_destroy net/core/dst_cache.c:160 [inline]
 dst_cache_destroy+0xcb/0x190 net/core/dst_cache.c:152
 ipip6_dev_free net/ipv6/sit.c:1414 [inline]
 sit_init_net+0x7d8/0xaa0 net/ipv6/sit.c:1936
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x40f/0xa30 net/core/net_namespace.c:326
 copy_net_ns+0x319/0x760 net/core/net_namespace.c:470
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3077
 __do_sys_unshare kernel/fork.c:3151 [inline]
 __se_sys_unshare kernel/fork.c:3149 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3149
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8f54a44a39
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:00007f8f51fba188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f8f54b47f60 RCX: 00007f8f54a44a39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000
RBP: 00007f8f54a9ec5f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffebc3f99af R14: 00007f8f51fba300 R15: 0000000000022000