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NetworkPkg: UefiPxeBcDxe: SECURITY PATCH CVE-2023-45234 Patch 

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=4539

Bug Details:
PixieFail Bug #6
CVE-2023-45234
CVSS 8.3 : CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H
CWE-119 Improper Restriction of Operations within the Bounds of
 a Memory Buffer

Buffer overflow when processing DNS Servers option in a DHCPv6
Advertise message

Change Overview:

Introduces a function to cache the Dns Server and perform sanitizing
on the incoming DnsServerLen to ensure that the length is valid

> + EFI_STATUS
> + PxeBcCacheDnsServerAddresses (
> +  IN PXEBC_PRIVATE_DATA        *Private,
> +  IN PXEBC_DHCP6_PACKET_CACHE  *Cache6
> +  )

Additional code cleanup

Cc: Saloni Kasbekar <saloni.kasbekar@intel.com>
Cc: Zachary Clark-williams <zachary.clark-williams@intel.com>

Signed-off-by: Doug Flick [MSFT] <doug.edk2@gmail.com>
Reviewed-by: Saloni Kasbekar <saloni.kasbekar@intel.com>
This commit is contained in:
Doug Flick 2024-01-26 05:54:52 +08:00 committed by mergify[bot]
parent c9c87f08dd
commit 1b53515d53
1 changed files with 65 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
View File

@ -3,6 +3,7 @@
(C) Copyright 2014 Hewlett-Packard Development Company, L.P.<BR>
Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
Copyright (c) Microsoft Corporation
SPDX-License-Identifier: BSD-2-Clause-Patent
@ -1312,6 +1313,65 @@ PxeBcSelectDhcp6Offer (
}
}
/**
Cache the DHCPv6 DNS Server addresses
@param[in] Private The pointer to PXEBC_PRIVATE_DATA.
@param[in] Cache6 The pointer to PXEBC_DHCP6_PACKET_CACHE.
@retval EFI_SUCCESS Cache the DHCPv6 DNS Server address successfully.
@retval EFI_OUT_OF_RESOURCES Failed to allocate resources.
@retval EFI_DEVICE_ERROR The DNS Server Address Length provided by a untrusted
option is not a multiple of 16 bytes (sizeof (EFI_IPv6_ADDRESS)).
**/
EFI_STATUS
PxeBcCacheDnsServerAddresses (
IN PXEBC_PRIVATE_DATA *Private,
IN PXEBC_DHCP6_PACKET_CACHE *Cache6
)
{
UINT16 DnsServerLen;
DnsServerLen = NTOHS (Cache6->OptList[PXEBC_DHCP6_IDX_DNS_SERVER]->OpLen);
//
// Make sure that the number is nonzero
//
if (DnsServerLen == 0) {
return EFI_DEVICE_ERROR;
}
//
// Make sure the DnsServerlen is a multiple of EFI_IPv6_ADDRESS (16)
//
if (DnsServerLen % sizeof (EFI_IPv6_ADDRESS) != 0) {
return EFI_DEVICE_ERROR;
}
//
// This code is currently written to only support a single DNS Server instead
// of multiple such as is spec defined (RFC3646, Section 3). The proper behavior
// would be to allocate the full space requested, CopyMem all of the data,
// and then add a DnsServerCount field to Private and update additional code
// that depends on this.
//
// To support multiple DNS servers the `AllocationSize` would need to be changed to DnsServerLen
//
// This is tracked in https://bugzilla.tianocore.org/show_bug.cgi?id=1886
//
Private->DnsServer = AllocateZeroPool (sizeof (EFI_IPv6_ADDRESS));
if (Private->DnsServer == NULL) {
return EFI_OUT_OF_RESOURCES;
}
//
// Intentionally only copy over the first server address.
// To support multiple DNS servers, the `Length` would need to be changed to DnsServerLen
//
CopyMem (Private->DnsServer, Cache6->OptList[PXEBC_DHCP6_IDX_DNS_SERVER]->Data, sizeof (EFI_IPv6_ADDRESS));
return EFI_SUCCESS;
}
/**
Handle the DHCPv6 offer packet.
@ -1335,6 +1395,7 @@ PxeBcHandleDhcp6Offer (
UINT32 SelectIndex;
UINT32 Index;
ASSERT (Private != NULL);
ASSERT (Private->SelectIndex > 0);
SelectIndex = (UINT32)(Private->SelectIndex - 1);
ASSERT (SelectIndex < PXEBC_OFFER_MAX_NUM);
@ -1342,15 +1403,13 @@ PxeBcHandleDhcp6Offer (
Status = EFI_SUCCESS;
//
// First try to cache DNS server address if DHCP6 offer provides.
// First try to cache DNS server addresses if DHCP6 offer provides.
//
if (Cache6->OptList[PXEBC_DHCP6_IDX_DNS_SERVER] != NULL) {
Private->DnsServer = AllocateZeroPool (NTOHS (Cache6->OptList[PXEBC_DHCP6_IDX_DNS_SERVER]->OpLen));
if (Private->DnsServer == NULL) {
return EFI_OUT_OF_RESOURCES;
Status = PxeBcCacheDnsServerAddresses (Private, Cache6);
if (EFI_ERROR (Status)) {
return Status;
}
CopyMem (Private->DnsServer, Cache6->OptList[PXEBC_DHCP6_IDX_DNS_SERVER]->Data, sizeof (EFI_IPv6_ADDRESS));
}
if (Cache6->OfferType == PxeOfferTypeDhcpBinl) {