------------[ cut here ]------------
WARNING: CPU: 0 PID: 15641 at net/ipv4/route.c:1259 kfree_skb include/linux/skbuff.h:1213 [inline]
WARNING: CPU: 0 PID: 15641 at net/ipv4/route.c:1259 ip_rt_bug+0x28/0x120 net/ipv4/route.c:1258
Modules linked in:
CPU: 0 PID: 15641 Comm: syz-executor.5 Not tainted 6.2.0-rc5-syzkaller-00997-g5c0862c2c962 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
RIP: 0010:ip_rt_bug+0x28/0x120 net/ipv4/route.c:1259
Code: 00 00 f3 0f 1e fa 41 54 55 48 89 d5 53 48 83 ec 08 e8 ac 44 3b f9 66 90 e8 a5 44 3b f9 be 02 00 00 00 48 89 ef e8 88 33 7e ff <0f> 0b 48 83 c4 08 31 c0 5b 5d 41 5c c3 e8 86 44 3b f9 48 8d 7d 10
RSP: 0018:ffffc90000007870 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88807921b980 RCX: 0000000000000100
RDX: ffff888043623a80 RSI: ffffffff88461c88 RDI: 0000000000000000
RBP: ffff8880228d2280 R08: 0000000000000000 R09: ffffffff91341b57
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88801e045300
R13: ffff8880228d2280 R14: 0000000000000000 R15: ffff8880228d22d8
FS:  00007f161cc41700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5645384998 CR3: 00000000895ce000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 dst_output include/net/dst.h:444 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb net/ipv4/ip_output.c:1586 [inline]
 ip_push_pending_frames+0x129/0x2b0 net/ipv4/ip_output.c:1606
 icmp_push_reply+0x319/0x440 net/ipv4/icmp.c:389
 __icmp_send+0xb80/0x13f0 net/ipv4/icmp.c:765
 ipv4_send_dest_unreach net/ipv4/route.c:1239 [inline]
 ipv4_link_failure+0x5aa/0x9b0 net/ipv4/route.c:1246
 dst_link_failure include/net/dst.h:423 [inline]
 arp_error_report+0xcb/0x1c0 net/ipv4/arp.c:296
 neigh_invalidate+0x20d/0x560 net/core/neighbour.c:1067
 neigh_timer_handler+0xd9e/0x1150 net/core/neighbour.c:1154
 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1700
 expire_timers+0x2c6/0x5c0 kernel/time/timer.c:1751
 __run_timers kernel/time/timer.c:2022 [inline]
 __run_timers kernel/time/timer.c:1995 [inline]
 run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035
 __do_softirq+0x1fb/0xadc kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:lock_acquire+0x227/0x630 kernel/locking/lockdep.c:5636
Code: 81 9e 7e 83 f8 01 0f 85 3a 03 00 00 9c 58 f6 c4 02 0f 85 25 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90009767a88 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920012ecf54 RCX: 33e43f4e8b8cb1d0
RDX: 1ffff110086c4896 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff91341ac7
R10: fffffbfff2268358 R11: 1ffff110110bf432 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8c791b00 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:325 [inline]
 rcu_read_lock include/linux/rcupdate.h:764 [inline]
 inet_twsk_purge+0x132/0x8a0 net/ipv4/inet_timewait_sock.c:295
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174
 setup_net+0x9bd/0xe60 net/core/net_namespace.c:356
 copy_net_ns+0x31b/0x6b0 net/core/net_namespace.c:483
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc5/0x1f0 kernel/nsproxy.c:228
 ksys_unshare+0x449/0x920 kernel/fork.c:3202
 __do_sys_unshare kernel/fork.c:3273 [inline]
 __se_sys_unshare kernel/fork.c:3271 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3271
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f161be8c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f161cc41168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f161bfac120 RCX: 00007f161be8c0c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f161bee7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdb8a02aaf R14: 00007f161cc41300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	81 9e 7e 83 f8 01 0f 	sbbl   $0x33a850f,0x1f8837e(%rsi)
   7:	85 3a 03
   a:	00 00                	add    %al,(%rax)
   c:	9c                   	pushfq
   d:	58                   	pop    %rax
   e:	f6 c4 02             	test   $0x2,%ah
  11:	0f 85 25 03 00 00    	jne    0x33c
  17:	48 83 7c 24 08 00    	cmpq   $0x0,0x8(%rsp)
  1d:	74 01                	je     0x20
  1f:	fb                   	sti
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	48 01 c3             	add    %rax,%rbx <-- trapping instruction
  2d:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
  34:	48 c7 43 08 00 00 00 	movq   $0x0,0x8(%rbx)
  3b:	00
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	84                   	.byte 0x84
  3f:	24                   	.byte 0x24