tyler.durden/audk
1
0
Fork 0
mirror of https://github.com/acidanthera/audk.git synced 2025-07-29 16:44:10 +02:00
Code Issues Packages Projects Releases Wiki Activity

NetworkPkg/DnsDxe: [CVE-2018-12178] Check the received packet size before parsing the message.

Browse Source 
Fix CVE-2018-12178
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=809

The DNS driver only checks the received packet size against the
minimum DNS header size in DnsOnPacketReceived(), later it accesses
the QueryName and QuerySection beyond the header scope, which might
cause the pointer within DNS driver points to an invalid entry or
modifies the memory content beyond the header scope.

This patch is to fix above problem.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Wang Fan <fan.wang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
Reviewed-by: Siyuan Fu <siyuan.fu@intel.com>
This commit is contained in:
Jiaxin Wu 2018-07-02 09:20:56 +08:00
parent 38c9fbdcaa
commit 84110bbe4b
2 changed files with 69 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
NetworkPkg/DnsDxe/DnsImpl.c
View File

@ -1114,6 +1114,7 @@ IsValidDnsResponse (
@param Instance The DNS instance
@param RxString Received buffer.
@param Length Received buffer length.
@param Completed Flag to indicate that Dns response is valid.
@retval EFI_SUCCESS Parse Dns Response successfully.
@ -1124,12 +1125,14 @@ EFI_STATUS
ParseDnsResponse (
IN OUT DNS_INSTANCE *Instance,
IN UINT8 *RxString,
IN UINT32 Length,
OUT BOOLEAN *Completed
)
{
DNS_HEADER *DnsHeader;
CHAR8 *QueryName;
UINT32 QueryNameLen;
DNS_QUERY_SECTION *QuerySection;
CHAR8 *AnswerName;
@ -1155,6 +1158,7 @@ ParseDnsResponse (
DNS6_RESOURCE_RECORD *Dns6RR;
EFI_STATUS Status;
UINT32 RemainingLength;
EFI_TPL OldTpl;
@ -1178,6 +1182,17 @@ ParseDnsResponse (
*Completed = TRUE;
Status = EFI_SUCCESS;
RemainingLength = Length;
//
// Check whether the remaining packet length is avaiable or not.
//
if (RemainingLength <= sizeof (DNS_HEADER)) {
*Completed = FALSE;
return EFI_ABORTED;
} else {
RemainingLength -= sizeof (DNS_HEADER);
}
//
// Get header
@ -1191,23 +1206,39 @@ ParseDnsResponse (
DnsHeader->AuthorityNum = NTOHS (DnsHeader->AuthorityNum);
DnsHeader->AditionalNum = NTOHS (DnsHeader->AditionalNum);
//
// There is always one QuestionsNum in DNS message. The capability to handle more
// than one requires to redesign the message format. Currently, it's not supported.
//
if (DnsHeader->QuestionsNum > 1) {
*Completed = FALSE;
return EFI_UNSUPPORTED;
}
//
// Get Query name
//
QueryName = (CHAR8 *) (RxString + sizeof (*DnsHeader));
QueryNameLen = (UINT32) AsciiStrLen (QueryName) + 1;
//
// Check whether the remaining packet length is avaiable or not.
//
if (RemainingLength <= QueryNameLen + sizeof (DNS_QUERY_SECTION)) {
*Completed = FALSE;
return EFI_ABORTED;
} else {
RemainingLength -= (QueryNameLen + sizeof (DNS_QUERY_SECTION));
}
//
// Get query section
//
QuerySection = (DNS_QUERY_SECTION *) (QueryName + AsciiStrLen (QueryName) + 1);
QuerySection = (DNS_QUERY_SECTION *) (QueryName + QueryNameLen);
QuerySection->Type = NTOHS (QuerySection->Type);
QuerySection->Class = NTOHS (QuerySection->Class);
//
// Get Answer name
//
AnswerName = (CHAR8 *) QuerySection + sizeof (*QuerySection);
OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
//
@ -1341,10 +1372,26 @@ ParseDnsResponse (
Status = EFI_NOT_FOUND;
//
// Get Answer name
//
AnswerName = (CHAR8 *) QuerySection + sizeof (*QuerySection);
//
// Processing AnswerSection.
//
while (AnswerSectionNum < DnsHeader->AnswersNum) {
//
// Check whether the remaining packet length is avaiable or not.
//
if (RemainingLength <= sizeof (UINT16) + sizeof (DNS_ANSWER_SECTION)) {
*Completed = FALSE;
Status = EFI_ABORTED;
goto ON_EXIT;
} else {
RemainingLength -= (sizeof (UINT16) + sizeof (DNS_ANSWER_SECTION));
}
//
// Answer name should be PTR, else EFI_UNSUPPORTED returned.
//
@ -1362,6 +1409,17 @@ ParseDnsResponse (
AnswerSection->Ttl = NTOHL (AnswerSection->Ttl);
AnswerSection->DataLength = NTOHS (AnswerSection->DataLength);
//
// Check whether the remaining packet length is avaiable or not.
//
if (RemainingLength < AnswerSection->DataLength) {
*Completed = FALSE;
Status = EFI_ABORTED;
goto ON_EXIT;
} else {
RemainingLength -= AnswerSection->DataLength;
}
//
// Check whether it's the GeneralLookUp querying.
//
@ -1733,6 +1791,7 @@ DnsOnPacketReceived (
DNS_INSTANCE *Instance;
UINT8 *RcvString;
UINT32 Len;
BOOLEAN Completed;
@ -1748,9 +1807,7 @@ DnsOnPacketReceived (
ASSERT (Packet != NULL);
if (Packet->TotalSize <= sizeof (DNS_HEADER)) {
goto ON_EXIT;
}
Len = Packet->TotalSize;
RcvString = NetbufGetByte (Packet, 0, NULL);
ASSERT (RcvString != NULL);
@ -1758,7 +1815,7 @@ DnsOnPacketReceived (
//
// Parse Dns Response
//
ParseDnsResponse (Instance, RcvString, &Completed);
ParseDnsResponse (Instance, RcvString, Len, &Completed);
ON_EXIT:

2
NetworkPkg/DnsDxe/DnsImpl.h
View File

@ -583,6 +583,7 @@ IsValidDnsResponse (
@param Instance The DNS instance
@param RxString Received buffer.
@param Length Received buffer length.
@param Completed Flag to indicate that Dns response is valid.
@retval EFI_SUCCESS Parse Dns Response successfully.
@ -593,6 +594,7 @@ EFI_STATUS
ParseDnsResponse (
IN OUT DNS_INSTANCE *Instance,
IN UINT8 *RxString,
IN UINT32 Length,
OUT BOOLEAN *Completed
);