internal/routebsd: fix parsing network address of length zero

This applies CL 646555 from the net repository to this copy.

For #70528

Change-Id: Ib7e23accfa3f278392e7bdca6f8544b8f1395e7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/646676
Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
TryBot-Bypass: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
This commit is contained in:
Ian Lance Taylor 2025-02-04 15:11:42 -08:00 committed by Gopher Robot
parent b7c9cdd53c
commit f6ea0621d2
2 changed files with 40 additions and 36 deletions

View File

@ -104,33 +104,40 @@ func parseInetAddr(af int, b []byte) (Addr, error) {
const (
off4 = 4 // offset of in_addr
off6 = 8 // offset of in6_addr
ipv4Len = 4 // length of IPv4 address in bytes
ipv6Len = 16 // length of IPv6 address in bytes
)
switch af {
case syscall.AF_INET:
if len(b) < (off4+1) || len(b) < int(b[0]) || b[0] == 0 {
if len(b) < (off4+1) || len(b) < int(b[0]) {
return nil, errInvalidAddr
}
sockAddrLen := int(b[0])
var ip [4]byte
n := off4 + 4
var ip [ipv4Len]byte
if sockAddrLen != 0 {
// Calculate how many bytes of the address to copy:
// either full IPv4 length or the available length.
n := off4 + ipv4Len
if sockAddrLen < n {
n = sockAddrLen
}
copy(ip[:], b[off4:n])
}
a := &InetAddr{
IP: netip.AddrFrom4(ip),
}
return a, nil
case syscall.AF_INET6:
if len(b) < (off6+1) || len(b) < int(b[0]) || b[0] == 0 {
if len(b) < (off6+1) || len(b) < int(b[0]) {
return nil, errInvalidAddr
}
var ip [ipv6Len]byte
sockAddrLen := int(b[0])
n := off6 + 16
if sockaddrLen != 0 {
n := off6 + ipv6Len
if sockAddrLen < n {
n = sockAddrLen
}
var ip [16]byte
copy(ip[:], b[off6:n])
if ip[0] == 0xfe && ip[1]&0xc0 == 0x80 || ip[0] == 0xff && (ip[1]&0x0f == 0x01 || ip[1]&0x0f == 0x02) {
// KAME based IPv6 protocol stack usually
@ -142,6 +149,7 @@ func parseInetAddr(af int, b []byte) (Addr, error) {
ip[2], ip[3] = 0, 0
}
}
}
// The kernel can provide an integer zone ID.
// We ignore it.
a := &InetAddr{
@ -251,16 +259,12 @@ func parseAddrs(attrs uint, b []byte) ([]Addr, error) {
}
b = b[l:]
case syscall.AF_INET, syscall.AF_INET6:
// #70528: if the sockaddrlen is 0, no address to parse inside,
// skip over the record.
if b[0] > 0 {
af = int(b[1])
a, err := parseInetAddr(af, b)
if err != nil {
return nil, err
}
as[i] = a
}
l := roundup(int(b[0]))
if len(b) < l {
return nil, errMessageTooShort

View File

@ -108,7 +108,7 @@ var parseAddrsOnDarwinLittleEndianTests = []parseAddrsOnDarwinTest{
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00,
},
[]Addr{
nil,
&InetAddr{IP: netip.AddrFrom16([16]byte{})},
&InetAddr{IP: netip.AddrFrom16([16]byte{0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x2f, 0x4b, 0xff, 0xfe, 0x09, 0x3b, 0xff})},
&InetAddr{IP: netip.AddrFrom16([16]byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff})},
nil,