Oops: general protection fault, probably for non-canonical address 0xdffffc0000000083: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000418-0x000000000000041f] CPU: 1 UID: 0 PID: 22519 Comm: syz.9.4783 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:270 [inline] RIP: 0010:fib_lookup_good_nhc+0x85/0x3d0 net/ipv4/fib_trie.c:1408 Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 6b ba 30 f8 41 bc 18 04 00 00 4c 03 23 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 4c ba 30 f8 4d 8b 24 24 e8 b3 e3 RSP: 0018:ffffc9000f4366f0 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff8880314f6120 RCX: 0000000000000002 RDX: ffff88806ab21e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880314f6137 R08: 0000000000000000 R09: ffffffff89d42e76 R10: ffffc9000f4369c0 R11: fffff52001e86d3e R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100629ec26 FS: 0000000000000000(0000) GS:ffff888125d52000(0063) knlGS:00000000f504eb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000002de1dffc CR3: 0000000064328000 CR4: 00000000003526f0 Call Trace: nexthop_get_nhc_lookup+0x1af/0x400 include/net/nexthop.h:437 fib_table_lookup+0xf26/0x16e0 net/ipv4/fib_trie.c:1584 fib_lookup+0x1c5/0x440 include/net/ip_fib.h:390 ip_route_output_key_hash_rcu+0x2fb/0x23a0 net/ipv4/route.c:2803 ip_route_output_key_hash+0x1b9/0x2e0 net/ipv4/route.c:2694 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2921 ip_route_output_ports include/net/route.h:213 [inline] ipip6_tunnel_bind_dev+0x214/0x610 net/ipv6/sit.c:1111 ipip6_tunnel_init+0xa5/0x570 net/ipv6/sit.c:1455 register_netdevice+0x6bc/0x1ae0 net/core/dev.c:11032 ipip6_tunnel_create+0x112/0x2c0 net/ipv6/sit.c:216 ipip6_newlink+0x306/0x5a0 net/ipv6/sit.c:1582 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3823 __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 ____sys_sendmsg+0x505/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmsg+0x164/0x220 net/socket.c:2652 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf705e539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f504e55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000040 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:270 [inline] RIP: 0010:fib_lookup_good_nhc+0x85/0x3d0 net/ipv4/fib_trie.c:1408 Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 6b ba 30 f8 41 bc 18 04 00 00 4c 03 23 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 4c ba 30 f8 4d 8b 24 24 e8 b3 e3 RSP: 0018:ffffc9000f4366f0 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff8880314f6120 RCX: 0000000000000002 RDX: ffff88806ab21e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880314f6137 R08: 0000000000000000 R09: ffffffff89d42e76 R10: ffffc9000f4369c0 R11: fffff52001e86d3e R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100629ec26 FS: 0000000000000000(0000) GS:ffff888125c52000(0063) knlGS:00000000f504eb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f74381e8 CR3: 0000000064328000 CR4: 00000000003526f0 DR0: 0000040000000000 DR1: 000000000000000c DR2: 0000000000000006 DR3: 0000000000000006 DR6: 00000000ffff0ff0 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 6b ba 30 f8 call 0xf830ba85 1a: 41 bc 18 04 00 00 mov $0x418,%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 4c ba 30 f8 call 0xf830ba85 39: 4d 8b 24 24 mov (%r12),%r12 3d: e8 .byte 0xe8 3e: b3 e3 mov $0xe3,%bl