general protection fault, probably for non-canonical address 0xdffffc000000006b: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000358-0x000000000000035f] CPU: 1 PID: 11813 Comm: syz.7.2032 Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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 8f a5 59 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 70 a5 59 f9 4d 8b 24 24 e8 67 0c RSP: 0018:ffffc9000301f538 EFLAGS: 00010202 RAX: 000000000000006b RBX: ffff888023563f20 RCX: ffff88804bdb0000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888023563f2f R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: 0000000000000358 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110046ac7e5 FS: 00007f3237d326c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000200 CR3: 0000000050fd9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000001000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nexthop_get_nhc_lookup+0x1a8/0x400 include/net/nexthop.h:405 fib_table_lookup+0xe76/0x15e0 net/ipv4/fib_trie.c:1583 fib_lookup+0x192/0x400 include/net/ip_fib.h:381 ip_route_output_key_hash_rcu+0x305/0x2460 net/ipv4/route.c:2785 ip_route_output_key_hash+0x1b1/0x2e0 net/ipv4/route.c:2675 __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x26/0x150 net/ipv4/route.c:2905 ip_route_output_key include/net/route.h:142 [inline] sctp_v4_get_dst+0x34d/0x10d0 net/sctp/protocol.c:449 sctp_transport_route+0x107/0x2b0 net/sctp/transport.c:463 sctp_assoc_add_peer+0x615/0x15a0 net/sctp/associola.c:665 sctp_connect_new_asoc+0x300/0x690 net/sctp/socket.c:1097 __sctp_connect+0x59e/0xd20 net/sctp/socket.c:1195 __sctp_setsockopt_connectx net/sctp/socket.c:1334 [inline] sctp_getsockopt_connectx3+0x2c0/0x440 net/sctp/socket.c:1419 sctp_getsockopt+0x3ab/0x8a0 net/sctp/socket.c:8122 __sys_getsockopt+0x206/0x430 net/socket.c:2247 __do_sys_getsockopt net/socket.c:2262 [inline] __se_sys_getsockopt net/socket.c:2259 [inline] __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2259 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: 0033:0x7f3239eca929 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:00007f3237d32038 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007f323a0f1fa0 RCX: 00007f3239eca929 RDX: 000000000000006f RSI: 0000000000000084 RDI: 0000000000000004 RBP: 00007f3239f4cb39 R08: 0000200000000140 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f323a0f1fa0 R15: 00007ffeb57031e8 Modules linked in: ---[ end trace 732db0921737fd44 ]--- 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 8f a5 59 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 70 a5 59 f9 4d 8b 24 24 e8 67 0c RSP: 0018:ffffc9000301f538 EFLAGS: 00010202 RAX: 000000000000006b RBX: ffff888023563f20 RCX: ffff88804bdb0000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888023563f2f R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: 0000000000000358 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110046ac7e5 FS: 00007f3237d326c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3230a25ab8 CR3: 0000000050fd9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000001000 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 8f a5 59 f9 call 0xf959a5a9 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 70 a5 59 f9 call 0xf959a5a9 39: 4d 8b 24 24 mov (%r12),%r12 3d: e8 .byte 0xe8 3e: 67 addr32 3f: 0c .byte 0xc