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: 19270 Comm: syz.4.3757 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #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 bb dc 2f 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 9c dc 2f f8 4d 8b 24 24 e8 d3 0a RSP: 0018:ffffc90004d0f4d0 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff88803b8f0820 RCX: 0000000000000002 RDX: ffff888032643c00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88803b8f0837 R08: 0000000000000000 R09: ffffffff89d50406 R10: ffffc90004d0f7a0 R11: fffff520009a1efa R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100771e106 FS: 0000000000000000(0000) GS:ffff888125c50000(0063) knlGS:00000000f50deb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000080004cc0 CR3: 000000004459e000 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_key include/net/route.h:179 [inline] sctp_v4_get_dst+0x3c7/0x1200 net/sctp/protocol.c:454 sctp_transport_route+0x115/0x2f0 net/sctp/transport.c:457 sctp_assoc_add_peer+0x657/0x13b0 net/sctp/associola.c:663 sctp_connect_new_asoc+0x30a/0x690 net/sctp/socket.c:1100 __sctp_connect+0x5ba/0xd50 net/sctp/socket.c:1198 sctp_connect net/sctp/socket.c:4820 [inline] sctp_inet_connect+0x12e/0x1e0 net/sctp/socket.c:4835 __sys_connect_file net/socket.c:2038 [inline] __sys_connect+0x313/0x440 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __ia32_sys_connect+0x7a/0x90 net/socket.c:2060 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: 0023:0xf70ee539 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:00000000f50de55c EFLAGS: 00000206 ORIG_RAX: 000000000000016a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080004cc0 RDX: 0000000000000010 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 bb dc 2f 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 9c dc 2f f8 4d 8b 24 24 e8 d3 0a RSP: 0018:ffffc90004d0f4d0 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff88803b8f0820 RCX: 0000000000000002 RDX: ffff888032643c00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88803b8f0837 R08: 0000000000000000 R09: ffffffff89d50406 R10: ffffc90004d0f7a0 R11: fffff520009a1efa R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100771e106 FS: 0000000000000000(0000) GS:ffff888125d50000(0063) knlGS:00000000f50deb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00005638adce6950 CR3: 000000004459e000 CR4: 00000000003526f0 DR0: 0000040000000000 DR1: 000000000000064f 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 bb dc 2f f8 call 0xf82fdcd5 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 9c dc 2f f8 call 0xf82fdcd5 39: 4d 8b 24 24 mov (%r12),%r12 3d: e8 .byte 0xe8 3e: d3 0a rorl %cl,(%rdx)