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From: "Doug Flick via groups.io" <dougflick=microsoft.com@groups.io>
To: devel@edk2.groups.io
Cc: Doug Flick <dougflick@microsoft.com>,
	Saloni Kasbekar <saloni.kasbekar@intel.com>,
	Zachary Clark-williams <zachary.clark-williams@intel.com>,
	"Doug Flick [MSFT]" <doug.edk2@gmail.com>
Subject: [edk2-devel] [PATCH v2 10/15] NetworkPkg: UefiPxeBcDxe: SECURITY PATCH CVE-2023-45234 Patch
Date: Thu, 25 Jan 2024 13:54:52 -0800	[thread overview]
Message-ID: <cfb02298674842a5f63dedf82e4b0610f440b284.1706219324.git.doug.edk2@gmail.com> (raw)
In-Reply-To: <cover.1706219324.git.doug.edk2@gmail.com>

From: Doug Flick <dougflick@microsoft.com>

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>
---
 NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c | 71 +++++++++++++++++++++++++---
 1 file changed, 65 insertions(+), 6 deletions(-)

diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
index 425e0cf8061d..2b2d372889a3 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
@@ -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) {
-- 
2.43.0



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  parent reply	other threads:[~2024-01-25 23:06 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-25 21:54 [edk2-devel] [PATCH v2 00/15] Security Patches for EDK II Network Stack Doug Flick via groups.io
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 01/15] NetworkPkg: Dhcp6Dxe: SECURITY PATCH CVE-2023-45230 Patch Doug Flick via groups.io
2024-02-01 19:35   ` Saloni Kasbekar
2024-02-05 13:41   ` bryan-bt.tan via groups.io
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 02/15] NetworkPkg: : Add Unit tests to CI and create Host Test DSC Doug Flick via groups.io
2024-02-01 19:36   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 03/15] NetworkPkg: Dhcp6Dxe: SECURITY PATCH CVE-2023-45230 Unit Tests Doug Flick via groups.io
2024-02-01 19:40   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 04/15] NetworkPkg: Dhcp6Dxe: SECURITY PATCH CVE-2023-45229 Patch Doug Flick via groups.io
2024-02-01 19:42   ` Saloni Kasbekar
2024-02-05 13:46   ` bryan-bt.tan via groups.io
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 05/15] NetworkPkg: Dhcp6Dxe: SECURITY PATCH CVE-2023-45229 Unit Tests Doug Flick via groups.io
2024-02-01 19:49   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 06/15] NetworkPkg: Ip6Dxe: SECURITY PATCH CVE-2023-45231 Patch Doug Flick via groups.io
2024-02-01 19:52   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 07/15] NetworkPkg: Ip6Dxe: SECURITY PATCH CVE-2023-45231 Unit Tests Doug Flick via groups.io
2024-02-01 19:59   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 08/15] NetworkPkg: Ip6Dxe: SECURITY PATCH CVE-2023-45232 Patch Doug Flick via groups.io
2024-02-01 20:48   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 09/15] NetworkPkg: Ip6Dxe: SECURITY PATCH CVE-2023-45232 Unit Tests Doug Flick via groups.io
2024-02-01 21:16   ` Saloni Kasbekar
2024-01-25 21:54 ` Doug Flick via groups.io [this message]
2024-02-01 21:22   ` [edk2-devel] [PATCH v2 10/15] NetworkPkg: UefiPxeBcDxe: SECURITY PATCH CVE-2023-45234 Patch Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 11/15] NetworkPkg: UefiPxeBcDxe: SECURITY PATCH CVE-2023-45234 Unit Tests Doug Flick via groups.io
2024-02-01 21:32   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 12/15] MdePkg: Test: Add gRT_GetTime Google Test Mock Doug Flick via groups.io
2024-01-26 19:52   ` Michael D Kinney
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 13/15] NetworkPkg: UefiPxeBcDxe: SECURITY PATCH CVE-2023-45235 Patch Doug Flick via groups.io
2024-02-01 21:37   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 14/15] NetworkPkg: UefiPxeBcDxe: SECURITY PATCH CVE-2023-45235 Unit Tests Doug Flick via groups.io
2024-02-01 22:03   ` Saloni Kasbekar
2024-01-25 21:54 ` [edk2-devel] [PATCH v2 15/15] NetworkPkg: : Adds a SecurityFix.yaml file Doug Flick via groups.io
2024-02-01 22:18   ` Saloni Kasbekar
2024-01-31  5:22 ` [edk2-devel] 回复: [edk2-stable202402][PATCH v2 00/15] Security Patches for EDK II Network Stack gaoliming via groups.io
     [not found] ` <17AF5718015C1866.16460@groups.io>
2024-02-07 14:26   ` 回复: " gaoliming via groups.io

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