------------[ cut here ]------------
dst_release underflow
WARNING: CPU: 0 PID: 62 at net/core/dst.c:173 dst_release net/core/dst.c:173 [inline]
WARNING: CPU: 0 PID: 62 at net/core/dst.c:173 dst_release+0xd2/0xe0 net/core/dst.c:167
Modules linked in:
CPU: 1 PID: 62 Comm: kworker/u4:3 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
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 3f 02 4a fa 85 db 74 a4 e9 5e b0 11 02 e8 11 00 4a fa 48 c7 c7 a0 ce ad 8a c6 05 23 01 4f 06 01 e8 d9 f5 d2 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:ffffc90001a3f9d8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888017aa0000 RSI: ffffffff815f1db8 RDI: fffff52000347f2d
RBP: ffffe8ffffc682f0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815ebb5e R11: 0000000000000000 R12: ffff888036b58d00
R13: 00000000ffffffff R14: 0000000000000007 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff31a1ec000 CR3: 0000000028e86000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 dst_cache_destroy net/core/dst_cache.c:160 [inline]
 dst_cache_destroy+0xcb/0x190 net/core/dst_cache.c:152
 ipip6_dev_free+0x15/0x50 net/ipv6/sit.c:1414
 netdev_run_todo+0x6b4/0xa80 net/core/dev.c:10630
 sit_exit_batch_net+0x535/0x750 net/ipv6/sit.c:1952
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>