syzbot

general protection fault, probably for non-canonical address 0xdffffc000000005c: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000002e0-0x00000000000002e7]
CPU: 1 PID: 15039 Comm: syz.5.3885 Not tainted 5.10.237-syzkaller-00309-g7e2543346ff7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__in6_dev_get include/net/addrconf.h:343 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:434 [inline]
RIP: 0010:find_match+0xa7/0xd60 net/ipv6/route.c:739
Code: 41 80 7c 05 00 00 74 08 4c 89 f7 e8 63 8c a9 fd 41 bc e0 02 00 00 4d 03 26 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 3b 8c a9 fd 4d 8b 24 24 4d 85 e4 0f
RSP: 0018:ffffc9000124e650 EFLAGS: 00010206
RAX: 000000000000005c RBX: 0000000000000002 RCX: dffffc0000000000
RDX: ffff88810d932780 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000124e6d8 R08: ffffc9000124ea00 R09: ffffc9000124ea10
R10: fffff52000249d62 R11: 1ffff92000249d5e R12: 00000000000002e0
R13: 1ffff110221d2e44 R14: ffff888110e97220 R15: 0000000000000000
FS:  00007ff8bac336c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000130fbb000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rt6_nh_find_match+0xd9/0x140 net/ipv6/route.c:779
 nexthop_for_each_fib6_nh+0xf6/0x1e0 net/ipv4/nexthop.c:602
 __find_rr_leaf+0x50f/0x900 net/ipv6/route.c:820
 find_rr_leaf net/ipv6/route.c:848 [inline]
 rt6_select net/ipv6/route.c:892 [inline]
 fib6_table_lookup+0x2f4/0x9f0 net/ipv6/route.c:2190
 ip6_pol_route+0x145/0x1110 net/ipv6/route.c:2226
 ip6_pol_route_output+0x51/0x80 net/ipv6/route.c:2475
 pol_lookup_func include/net/ip6_fib.h:594 [inline]
 fib6_rule_lookup+0x2ef/0x560 net/ipv6/fib6_rules.c:120
 ip6_route_output_flags_noref+0x248/0x2f0 net/ipv6/route.c:2507
 ip6_route_output_flags+0x3c/0x200 net/ipv6/route.c:2520
 ip6_dst_lookup_tail+0x1b9/0x1210 net/ipv6/ip6_output.c:1117
 ip6_dst_lookup_flow+0x49/0xc0 net/ipv6/ip6_output.c:1220
 tcp_v6_send_response+0xa40/0x1100 net/ipv6/tcp_ipv6.c:989
 tcp_v6_send_reset+0x52f/0x8b0 net/ipv6/tcp_ipv6.c:1101
 tcp_v6_do_rcv+0x7bc/0xfa0 net/ipv6/tcp_ipv6.c:1533
 tcp_v6_rcv+0x1d4c/0x2370 net/ipv6/tcp_ipv6.c:1721
 ip6_protocol_deliver_rcu+0xa77/0x1340 net/ipv6/ip6_input.c:427
 ip6_input_finish net/ipv6/ip6_input.c:468 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_input+0xd6/0x1f0 net/ipv6/ip6_input.c:477
 dst_input include/net/dst.h:461 [inline]
 ip6_rcv_finish+0x18c/0x360 net/ipv6/ip6_input.c:80
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0xec/0x210 net/ipv6/ip6_input.c:301
 __netif_receive_skb_one_core net/core/dev.c:5402 [inline]
 __netif_receive_skb+0xc8/0x280 net/core/dev.c:5516
 netif_receive_skb_internal net/core/dev.c:5621 [inline]
 netif_receive_skb+0x9b/0x3d0 net/core/dev.c:5680
 tun_rx_batched+0x5e8/0x710 drivers/net/tun.c:-1
 tun_get_user+0x25d0/0x3090 drivers/net/tun.c:2026
 tun_chr_write_iter+0x1bf/0x270 drivers/net/tun.c:2059
 call_write_iter include/linux/fs.h:2058 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x725/0xd60 fs/read_write.c:605
 ksys_write+0x140/0x240 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7ff8bc5c941f
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:00007ff8bac33000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff8bc7f1fa0 RCX: 00007ff8bc5c941f
RDX: 000000000000004a RSI: 00002000000001c0 RDI: 00000000000000c8
RBP: 00007ff8bc64cab1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000004a R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff8bc7f1fa0 R15: 00007ffec1a57c18
Modules linked in:
---[ end trace df190ff9f8711ac7 ]---
RIP: 0010:__in6_dev_get include/net/addrconf.h:343 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:434 [inline]
RIP: 0010:find_match+0xa7/0xd60 net/ipv6/route.c:739
Code: 41 80 7c 05 00 00 74 08 4c 89 f7 e8 63 8c a9 fd 41 bc e0 02 00 00 4d 03 26 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 3b 8c a9 fd 4d 8b 24 24 4d 85 e4 0f
RSP: 0018:ffffc9000124e650 EFLAGS: 00010206
RAX: 000000000000005c RBX: 0000000000000002 RCX: dffffc0000000000
RDX: ffff88810d932780 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000124e6d8 R08: ffffc9000124ea00 R09: ffffc9000124ea10
R10: fffff52000249d62 R11: 1ffff92000249d5e R12: 00000000000002e0
R13: 1ffff110221d2e44 R14: ffff888110e97220 R15: 0000000000000000
FS:  00007ff8bac336c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000130fbb000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	41 80 7c 05 00 00    	cmpb   $0x0,0x0(%r13,%rax,1)
   6:	74 08                	je     0x10
   8:	4c 89 f7             	mov    %r14,%rdi
   b:	e8 63 8c a9 fd       	call   0xfda98c73
  10:	41 bc e0 02 00 00    	mov    $0x2e0,%r12d
  16:	4d 03 26             	add    (%r14),%r12
  19:	4c 89 e0             	mov    %r12,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 e7             	mov    %r12,%rdi
  33:	e8 3b 8c a9 fd       	call   0xfda98c73
  38:	4d 8b 24 24          	mov    (%r12),%r12
  3c:	4d 85 e4             	test   %r12,%r12
  3f:	0f                   	.byte 0xf