Oops: general protection fault, probably for non-canonical address 0xdffffc0000000083: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000418-0x000000000000041f] CPU: 0 UID: 0 PID: 13690 Comm: syz.4.1801 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 8b 12 1b 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 6c 12 1b f8 4d 8b 24 24 e8 13 c5 RSP: 0018:ffffc900033270d8 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff888078730320 RCX: 0000000000000002 RDX: ffff88801e389e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888078730337 R08: 0000000000000000 R09: ffffffff89e932b6 R10: ffffc900033273a0 R11: fffff52000664e7a R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100f0e6066 FS: 0000000000000000(0000) GS:ffff888125c18000(0063) knlGS:00000000f54acb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000003361cffc CR3: 0000000028da2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 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+0x31b/0x23e0 net/ipv4/route.c:2809 ip_route_output_key_hash+0x1b9/0x2e0 net/ipv4/route.c:2700 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2927 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:11133 ipip6_tunnel_create+0x112/0x2c0 net/ipv6/sit.c:216 ipip6_tunnel_locate+0x539/0x770 net/ipv6/sit.c:274 ipip6_tunnel_add net/ipv6/sit.c:1297 [inline] ipip6_tunnel_ctl+0x6b0/0x9e0 net/ipv6/sit.c:1362 addrconf_set_sit_dstaddr net/ipv6/addrconf.c:2959 [inline] addrconf_set_dstaddr+0x23b/0x2d0 net/ipv6/addrconf.c:2988 inet6_ioctl+0x152/0x280 net/ipv6/af_inet6.c:584 sock_do_ioctl+0xdc/0x300 net/socket.c:1238 compat_sock_ioctl_trans net/socket.c:3529 [inline] compat_sock_ioctl+0xb8d/0xc80 net/socket.c:3555 __do_compat_sys_ioctl fs/ioctl.c:696 [inline] __se_compat_sys_ioctl fs/ioctl.c:639 [inline] __ia32_compat_sys_ioctl+0x540/0x840 fs/ioctl.c:639 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: 0023:0xf70fe539 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:00000000f54ac55c EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000000008918 RDX: 0000000080000080 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 8b 12 1b 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 6c 12 1b f8 4d 8b 24 24 e8 13 c5 RSP: 0018:ffffc900033270d8 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff888078730320 RCX: 0000000000000002 RDX: ffff88801e389e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888078730337 R08: 0000000000000000 R09: ffffffff89e932b6 R10: ffffc900033273a0 R11: fffff52000664e7a R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100f0e6066 FS: 0000000000000000(0000) GS:ffff888125c18000(0063) knlGS:00000000f54acb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f758ed1c CR3: 0000000028da2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e 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 8b 12 1b f8 call 0xf81b12a5 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 6c 12 1b f8 call 0xf81b12a5 39: 4d 8b 24 24 mov (%r12),%r12 3d: e8 .byte 0xe8 3e: 13 c5 adc %ebp,%eax