------------[ cut here ]------------
WARNING: CPU: 0 PID: 23486 at net/ipv4/route.c:1270 ip_rt_bug+0x2c/0x110
Modules linked in:
CPU: 0 UID: 0 PID: 23486 Comm: syz.1.7213 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:ip_rt_bug+0x2c/0x110
Code: 1e fa 41 57 41 56 41 55 41 54 53 48 89 d3 e8 0b 46 0f f8 66 90 e8 04 46 0f f8 31 ff 48 89 de ba 02 00 00 00 e8 45 01 6f ff 90 <0f> 0b 90 31 c0 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc cc f3 0f
RSP: 0018:ffffc900087b7180 EFLAGS: 00010286
RAX: f3b3aa12f7048300 RBX: ffff88801d1b0d80 RCX: f3b3aa12f7048300
RDX: 0000000000000002 RSI: ffffffff8d70d466 RDI: ffffffff8bbf0860
RBP: 0000000000000001 R08: ffffffff8f7cdc77 R09: 1ffffffff1ef9b8e
R10: dffffc0000000000 R11: fffffbfff1ef9b8f R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88801d1b0d80 R15: ffff888102bc9e00
FS:  00007fe514dee6c0(0000) GS:ffff88818eb3d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2e458a CR3: 0000000169c14000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 ip_push_pending_frames+0xbe/0x150
 __icmp_send+0xfc3/0x1320
 ip_options_compile+0x80/0xb0
 ip_rcv_finish_core+0xaa2/0x1c00
 ip_rcv_finish+0x14c/0x2f0
 NF_HOOK+0x30c/0x3a0
 __netif_receive_skb+0x143/0x380
 netif_receive_skb+0x1cb/0x790
 tun_rx_batched+0x1b9/0x730
 tun_get_user+0x2b65/0x3e90
 tun_chr_write_iter+0x113/0x200
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe516b8da7f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fe514dee000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe516de5fa0 RCX: 00007fe516b8da7f
RDX: 0000000000000046 RSI: 0000200000000400 RDI: 00000000000000c8
RBP: 00007fe516c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000046 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fe516de6038 R14: 00007fe516de5fa0 R15: 00007ffee0c4cbb8
 </TASK>
