diff options
Diffstat (limited to 'pkg/tcpip/network')
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 16 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4_test.go | 104 |
2 files changed, 120 insertions, 0 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 162aa1b4d..fb6358fbb 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -296,6 +296,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { headerView := vv.First() h := header.IPv4(headerView) if !h.IsValid(vv.Size()) { + r.Stats().IP.MalformedPacketsReceived.Increment() return } @@ -306,8 +307,23 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { more := (h.Flags() & header.IPv4FlagMoreFragments) != 0 if more || h.FragmentOffset() != 0 { + if vv.Size() == 0 { + // Drop the packet as it's marked as a fragment but has + // no payload. + r.Stats().IP.MalformedPacketsReceived.Increment() + r.Stats().IP.MalformedFragmentsReceived.Increment() + return + } // The packet is a fragment, let's try to reassemble it. last := h.FragmentOffset() + uint16(vv.Size()) - 1 + // Drop the packet if the fragmentOffset is incorrect. i.e the + // combination of fragmentOffset and vv.size() causes a wrap + // around resulting in last being less than the offset. + if last < h.FragmentOffset() { + r.Stats().IP.MalformedPacketsReceived.Increment() + r.Stats().IP.MalformedFragmentsReceived.Increment() + return + } var ready bool vv, ready = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, more, vv) if !ready { diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go index 8b7500095..3dcb503e2 100644 --- a/pkg/tcpip/network/ipv4/ipv4_test.go +++ b/pkg/tcpip/network/ipv4/ipv4_test.go @@ -366,3 +366,107 @@ func TestFragmentationErrors(t *testing.T) { }) } } + +func TestInvalidFragments(t *testing.T) { + // These packets have both IHL and TotalLength set to 0. + testCases := []struct { + name string + packets [][]byte + wantMalformedIPPackets uint64 + wantMalformedFragments uint64 + }{ + { + "ihl_totallen_zero_valid_frag_offset", + [][]byte{ + {0x40, 0x30, 0x00, 0x00, 0x6c, 0x74, 0x7d, 0x30, 0x30, 0x30, 0x30, 0x30, 0x39, 0x32, 0x39, 0x33, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 1, + 0, + }, + { + "ihl_totallen_zero_invalid_frag_offset", + [][]byte{ + {0x40, 0x30, 0x00, 0x00, 0x6c, 0x74, 0x20, 0x00, 0x30, 0x30, 0x30, 0x30, 0x39, 0x32, 0x39, 0x33, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 1, + 0, + }, + { + // Total Length of 37(20 bytes IP header + 17 bytes of + // payload) + // Frag Offset of 0x1ffe = 8190*8 = 65520 + // Leading to the fragment end to be past 65535. + "ihl_totallen_valid_invalid_frag_offset_1", + [][]byte{ + {0x45, 0x30, 0x00, 0x25, 0x6c, 0x74, 0x1f, 0xfe, 0x30, 0x30, 0x30, 0x30, 0x39, 0x32, 0x39, 0x33, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 1, + 1, + }, + // The following 3 tests were found by running a fuzzer and were + // triggering a panic in the IPv4 reassembler code. + { + "ihl_less_than_ipv4_minimum_size_1", + [][]byte{ + {0x42, 0x30, 0x0, 0x30, 0x30, 0x40, 0x0, 0xf3, 0x30, 0x1, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + {0x42, 0x30, 0x0, 0x8, 0x30, 0x40, 0x20, 0x0, 0x30, 0x1, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 2, + 0, + }, + { + "ihl_less_than_ipv4_minimum_size_2", + [][]byte{ + {0x42, 0x30, 0x0, 0x30, 0x30, 0x40, 0xb3, 0x12, 0x30, 0x6, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + {0x42, 0x30, 0x0, 0x8, 0x30, 0x40, 0x20, 0x0, 0x30, 0x6, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 2, + 0, + }, + { + "ihl_less_than_ipv4_minimum_size_3", + [][]byte{ + {0x42, 0x30, 0x0, 0x30, 0x30, 0x40, 0xb3, 0x30, 0x30, 0x6, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + {0x42, 0x30, 0x0, 0x8, 0x30, 0x40, 0x20, 0x0, 0x30, 0x6, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 2, + 0, + }, + { + "fragment_with_short_total_len_extra_payload", + [][]byte{ + {0x46, 0x30, 0x00, 0x30, 0x30, 0x40, 0x0e, 0x12, 0x30, 0x06, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + {0x46, 0x30, 0x00, 0x18, 0x30, 0x40, 0x20, 0x00, 0x30, 0x06, 0x30, 0x30, 0x73, 0x73, 0x69, 0x6e, 0xff, 0xff, 0xff, 0xff, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30}, + }, + 1, + 1, + }, + } + + for _, tc := range testCases { + t.Run(tc.name, func(t *testing.T) { + const nicid tcpip.NICID = 42 + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ + ipv4.NewProtocol(), + }, + }) + + var linkAddr = tcpip.LinkAddress([]byte{0x30, 0x30, 0x30, 0x30, 0x30, 0x30}) + var remoteLinkAddr = tcpip.LinkAddress([]byte{0x30, 0x30, 0x30, 0x30, 0x30, 0x31}) + ep := channel.New(10, 1500, linkAddr) + s.CreateNIC(nicid, sniffer.New(ep)) + + for _, pkt := range tc.packets { + ep.InjectLinkAddr(header.IPv4ProtocolNumber, remoteLinkAddr, buffer.NewVectorisedView(len(pkt), []buffer.View{pkt})) + } + + if got, want := s.Stats().IP.MalformedPacketsReceived.Value(), tc.wantMalformedIPPackets; got != want { + t.Errorf("incorrect Stats.IP.MalformedPacketsReceived, got: %d, want: %d", got, want) + } + if got, want := s.Stats().IP.MalformedFragmentsReceived.Value(), tc.wantMalformedFragments; got != want { + t.Errorf("incorrect Stats.IP.MalformedFragmentsReceived, got: %d, want: %d", got, want) + } + }) + } +} |