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: 20801 Comm: syz.6.4563 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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 9b 3d 1a 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 7c 3d 1a f8 4d 8b 24 24 e8 33 f8 RSP: 0018:ffffc900046d72b0 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff888031ccf520 RCX: 0000000000000002 RDX: ffff88801a56bc00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888031ccf537 R08: 0000000000000000 R09: ffffffff8a0ef05f R10: 0000000000000008 R11: 0000000000000002 R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff11006399ea6 FS: 00007fc0e1aaa6c0(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc0e1aa9f98 CR3: 000000004cf38000 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 fib4_rule_action+0x1fb/0x330 net/ipv4/fib_rules.c:139 fib_rules_lookup+0x8a6/0xe90 net/core/fib_rules.c:339 __fib_lookup+0xf9/0x200 net/ipv4/fib_rules.c:96 ip_route_output_key_hash_rcu+0x31b/0x23e0 net/ipv4/route.c:2809 ip_route_output_key_hash+0x174/0x280 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_key include/net/route.h:179 [inline] sctp_v4_get_dst+0x3c7/0x1200 net/sctp/protocol.c:455 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:1099 __sctp_connect+0x5ba/0xd50 net/sctp/socket.c:1197 sctp_connect net/sctp/socket.c:4819 [inline] sctp_inet_connect+0x12e/0x1e0 net/sctp/socket.c:4834 __sys_connect_file net/socket.c:2086 [inline] __sys_connect+0x313/0x440 net/socket.c:2105 __do_sys_connect net/socket.c:2111 [inline] __se_sys_connect net/socket.c:2108 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc0e0b8eba9 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:00007fc0e1aaa038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007fc0e0dd6180 RCX: 00007fc0e0b8eba9 RDX: 0000000000000010 RSI: 0000200000004cc0 RDI: 000000000000000d RBP: 00007fc0e0c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc0e0dd6218 R14: 00007fc0e0dd6180 R15: 00007ffcf8709e18 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 9b 3d 1a 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 7c 3d 1a f8 4d 8b 24 24 e8 33 f8 RSP: 0018:ffffc900046d72b0 EFLAGS: 00010202 RAX: 0000000000000083 RBX: ffff888031ccf520 RCX: 0000000000000002 RDX: ffff88801a56bc00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888031ccf537 R08: 0000000000000000 R09: ffffffff8a0ef05f R10: 0000000000000008 R11: 0000000000000002 R12: 0000000000000418 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff11006399ea6 FS: 00007fc0e1aaa6c0(0000) GS:ffff888125d13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc0e1a68d58 CR3: 000000004cf38000 CR4: 00000000003526f0 ---------------- 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 9b 3d 1a f8 call 0xf81a3db5 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 7c 3d 1a f8 call 0xf81a3db5 39: 4d 8b 24 24 mov (%r12),%r12 3d: e8 .byte 0xe8 3e: 33 f8 xor %eax,%edi