general protection fault, probably for non-canonical address 0xdffffc000000006b: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000358-0x000000000000035f]
CPU: 0 PID: 6598 Comm: syz.3.639 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:254 [inline]
RIP: 0010:fib_lookup_good_nhc+0x81/0x3d0 net/ipv4/fib_trie.c:1407
Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 ef 5b 51 f9 41 bc 58 03 00 00 4c 03 23 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 d0 5b 51 f9 4d 8b 24 24 e8 77 1e
RSP: 0018:ffffc9000357e598 EFLAGS: 00010202
RAX: 000000000000006b RBX: ffff888019585820 RCX: ffff88805c280000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801958582f R08: dffffc0000000000 R09: fffffbfff1ff7619
R10: fffffbfff1ff7619 R11: 1ffffffff1ff7618 R12: 0000000000000358
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110032b0b05
FS: 00007f2ed92c16c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2ed92c0f98 CR3: 0000000023546000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nexthop_get_nhc_lookup+0x1a8/0x400 include/net/nexthop.h:405
fib_table_lookup+0xe76/0x15e0 net/ipv4/fib_trie.c:1583
fib4_rule_action+0x1cf/0x2f0 net/ipv4/fib_rules.c:135
fib_rules_lookup+0x5ab/0xaf0 net/core/fib_rules.c:318
__fib_lookup+0xf6/0x200 net/ipv4/fib_rules.c:92
ip_route_output_key_hash_rcu+0x2ec/0x24d0 net/ipv4/route.c:2788
ip_route_output_key_hash+0x1b1/0x2e0 net/ipv4/route.c:2678
__ip_route_output_key include/net/route.h:126 [inline]
ip_route_output_flow+0x26/0x150 net/ipv4/route.c:2908
ip_route_output_key include/net/route.h:142 [inline]
ip_tunnel_bind_dev+0x236/0x710 net/ipv4/ip_tunnel.c:299
ip_tunnel_newlink+0x713/0xc30 net/ipv4/ip_tunnel.c:1186
ipgre_newlink+0x29d/0x380 net/ipv4/ip_gre.c:1378
__rtnl_newlink net/core/rtnetlink.c:3524 [inline]
rtnl_newlink+0x114c/0x17d0 net/core/rtnetlink.c:3572
rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
__sys_sendmsg net/socket.c:2519 [inline]
__do_sys_sendmsg net/socket.c:2528 [inline]
__se_sys_sendmsg+0x190/0x250 net/socket.c:2526
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2edb07abe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2ed92c1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2edb2b2090 RCX: 00007f2edb07abe9
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f2edb0fde19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2edb2b2128 R14: 00007f2edb2b2090 R15: 00007ffdf53efd48
</TASK>
Modules linked in:
---[ end trace 946f4e66b0acb396 ]---
RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:254 [inline]
RIP: 0010:fib_lookup_good_nhc+0x81/0x3d0 net/ipv4/fib_trie.c:1407
Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 ef 5b 51 f9 41 bc 58 03 00 00 4c 03 23 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 d0 5b 51 f9 4d 8b 24 24 e8 77 1e
RSP: 0018:ffffc9000357e598 EFLAGS: 00010202
RAX: 000000000000006b RBX: ffff888019585820 RCX: ffff88805c280000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801958582f R08: dffffc0000000000 R09: fffffbfff1ff7619
R10: fffffbfff1ff7619 R11: 1ffffffff1ff7618 R12: 0000000000000358
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110032b0b05
FS: 00007f2ed92c16c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010038 CR3: 0000000023546000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 4c 89 24 24 mov %r12,(%rsp)
4: 48 89 d8 mov %rbx,%rax
7: 48 c1 e8 03 shr $0x3,%rax
b: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
10: 74 08 je 0x1a
12: 48 89 df mov %rbx,%rdi
15: e8 ef 5b 51 f9 call 0xf9515c09
1a: 41 bc 58 03 00 00 mov $0x358,%r12d
20: 4c 03 23 add (%rbx),%r12
23: 4c 89 e0 mov %r12,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 e7 mov %r12,%rdi
34: e8 d0 5b 51 f9 call 0xf9515c09
39: 4d 8b 24 24 mov (%r12),%r12
3d: e8 .byte 0xe8
3e: 77 1e ja 0x5e