------------[ cut here ]------------
WARNING: CPU: 0 PID: 9721 at net/ipv4/route.c:1241 ip_rt_bug+0x2b/0x120 net/ipv4/route.c:1241
Modules linked in:
CPU: 0 UID: 0 PID: 9721 Comm: syz.3.1039 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ip_rt_bug+0x2b/0x120 net/ipv4/route.c:1241
Code: 0f 1e fa 41 54 55 53 48 89 d3 48 83 ec 08 e8 3c 10 0c f8 66 90 e8 35 10 0c f8 ba 02 00 00 00 48 89 de 31 ff e8 d6 8c 74 ff 90 <0f> 0b 90 48 83 c4 08 31 c0 5b 5d 41 5c c3 cc cc cc cc e8 0e 10 0c
RSP: 0018:ffffc900034772f0 EFLAGS: 00010283
RAX: 0000000000000e73 RBX: ffff88802942e280 RCX: ffffc90007ab6000
RDX: 0000000000040000 RSI: ffffffff89816b3a RDI: ffffffff8bd1b6c0
RBP: ffff88802942e280 R08: 0000000000000001 R09: fffffbfff2dc5d9c
R10: ffffffff96e2ece7 R11: 0000000000000000 R12: ffff888035ad0000
R13: ffff888020cb6c00 R14: ffff8880328f0c00 R15: ffff88802942e2d8
FS:  00007fa049b326c0(0000) GS:ffff88806a600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563d4c1a36b8 CR3: 000000004ee54000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 dst_output include/net/dst.h:450 [inline]
 dst_output include/net/dst.h:448 [inline]
 ip_local_out net/ipv4/ip_output.c:130 [inline]
 ip_send_skb net/ipv4/ip_output.c:1496 [inline]
 ip_push_pending_frames+0x3ad/0x5b0 net/ipv4/ip_output.c:1516
 icmp_push_reply+0x308/0x440 net/ipv4/icmp.c:393
 __icmp_send+0xb88/0x1870 net/ipv4/icmp.c:780
 icmp_send include/net/icmp.h:43 [inline]
 __udp4_lib_rcv+0x1726/0x34e0 net/ipv4/udp.c:2461
 ip_protocol_deliver_rcu+0x2ff/0x4c0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:460 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5670
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5783
 netif_receive_skb_internal net/core/dev.c:5869 [inline]
 netif_receive_skb+0x13f/0x7b0 net/core/dev.c:5928
 tun_rx_batched+0x429/0x780 drivers/net/tun.c:1574
 tun_get_user+0x2a4d/0x3d80 drivers/net/tun.c:2007
 tun_chr_write_iter+0xdc/0x210 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x5ae/0x1150 fs/read_write.c:683
 ksys_write+0x12f/0x260 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa048d7d1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 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 1c 8e 02 00 48
RSP: 002b:00007fa049b32000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa048f35f80 RCX: 00007fa048d7d1ff
RDX: 00000000000000be RSI: 0000000020000100 RDI: 00000000000000c8
RBP: 00007fa048df175e R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000000be R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa048f35f80 R15: 00007ffffa7791b8
 </TASK>