diff options
| -rw-r--r-- | NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c | 77 | ||||
| -rw-r--r-- | NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.h | 17 |
2 files changed, 78 insertions, 16 deletions
diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c index 2b2d372889..7fd1281c11 100644 --- a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c +++ b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c @@ -887,6 +887,7 @@ PxeBcRequestBootService ( EFI_STATUS Status;
EFI_DHCP6_PACKET *IndexOffer;
UINT8 *Option;
+ UINTN DiscoverLenNeeded;
PxeBc = &Private->PxeBc;
Request = Private->Dhcp6Request;
@@ -899,7 +900,8 @@ PxeBcRequestBootService ( return EFI_DEVICE_ERROR;
}
- Discover = AllocateZeroPool (sizeof (EFI_PXE_BASE_CODE_DHCPV6_PACKET));
+ DiscoverLenNeeded = sizeof (EFI_PXE_BASE_CODE_DHCPV6_PACKET);
+ Discover = AllocateZeroPool (DiscoverLenNeeded);
if (Discover == NULL) {
return EFI_OUT_OF_RESOURCES;
}
@@ -924,16 +926,34 @@ PxeBcRequestBootService ( DHCP6_OPT_SERVER_ID
);
if (Option == NULL) {
- return EFI_NOT_FOUND;
+ Status = EFI_NOT_FOUND;
+ goto ON_ERROR;
}
//
// Add Server ID Option.
//
OpLen = NTOHS (((EFI_DHCP6_PACKET_OPTION *)Option)->OpLen);
- CopyMem (DiscoverOpt, Option, OpLen + 4);
- DiscoverOpt += (OpLen + 4);
- DiscoverLen += (OpLen + 4);
+
+ //
+ // Check that the minimum and maximum requirements are met
+ //
+ if ((OpLen < PXEBC_MIN_SIZE_OF_DUID) || (OpLen > PXEBC_MAX_SIZE_OF_DUID)) {
+ Status = EFI_INVALID_PARAMETER;
+ goto ON_ERROR;
+ }
+
+ //
+ // Check that the option length is valid.
+ //
+ if ((DiscoverLen + OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN) > DiscoverLenNeeded) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto ON_ERROR;
+ }
+
+ CopyMem (DiscoverOpt, Option, OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ DiscoverOpt += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ DiscoverLen += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
}
while (RequestLen < Request->Length) {
@@ -945,15 +965,23 @@ PxeBcRequestBootService ( )
{
//
+ // Check that the option length is valid.
+ //
+ if (DiscoverLen + OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN > DiscoverLenNeeded) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto ON_ERROR;
+ }
+
+ //
// Copy all the options except IA option and Server ID
//
- CopyMem (DiscoverOpt, RequestOpt, OpLen + 4);
- DiscoverOpt += (OpLen + 4);
- DiscoverLen += (OpLen + 4);
+ CopyMem (DiscoverOpt, RequestOpt, OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ DiscoverOpt += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ DiscoverLen += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
}
- RequestOpt += (OpLen + 4);
- RequestLen += (OpLen + 4);
+ RequestOpt += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ RequestLen += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
}
//
@@ -2154,6 +2182,7 @@ PxeBcDhcp6Discover ( UINT16 OpLen;
UINT32 Xid;
EFI_STATUS Status;
+ UINTN DiscoverLenNeeded;
PxeBc = &Private->PxeBc;
Mode = PxeBc->Mode;
@@ -2169,7 +2198,8 @@ PxeBcDhcp6Discover ( return EFI_DEVICE_ERROR;
}
- Discover = AllocateZeroPool (sizeof (EFI_PXE_BASE_CODE_DHCPV6_PACKET));
+ DiscoverLenNeeded = sizeof (EFI_PXE_BASE_CODE_DHCPV6_PACKET);
+ Discover = AllocateZeroPool (DiscoverLenNeeded);
if (Discover == NULL) {
return EFI_OUT_OF_RESOURCES;
}
@@ -2185,22 +2215,37 @@ PxeBcDhcp6Discover ( DiscoverLen = sizeof (EFI_DHCP6_HEADER);
RequestLen = DiscoverLen;
+ //
+ // The request packet is generated by the UEFI network stack. In the DHCP4 DORA and DHCP6 SARR sequence,
+ // the first (discover in DHCP4 and solicit in DHCP6) and third (request in both DHCP4 and DHCP6) are
+ // generated by the DHCP client (the UEFI network stack in this case). By the time this function executes,
+ // the DHCP sequence already has been executed once (see UEFI Specification Figures 24.2 and 24.3), with
+ // Private->Dhcp6Request being a cached copy of the DHCP6 request packet that UEFI network stack previously
+ // generated and sent.
+ //
+ // Therefore while this code looks like it could overflow, in practice it's not possible.
+ //
while (RequestLen < Request->Length) {
OpCode = NTOHS (((EFI_DHCP6_PACKET_OPTION *)RequestOpt)->OpCode);
OpLen = NTOHS (((EFI_DHCP6_PACKET_OPTION *)RequestOpt)->OpLen);
if ((OpCode != EFI_DHCP6_IA_TYPE_NA) &&
(OpCode != EFI_DHCP6_IA_TYPE_TA))
{
+ if (DiscoverLen + OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN > DiscoverLenNeeded) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto ON_ERROR;
+ }
+
//
// Copy all the options except IA option.
//
- CopyMem (DiscoverOpt, RequestOpt, OpLen + 4);
- DiscoverOpt += (OpLen + 4);
- DiscoverLen += (OpLen + 4);
+ CopyMem (DiscoverOpt, RequestOpt, OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ DiscoverOpt += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ DiscoverLen += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
}
- RequestOpt += (OpLen + 4);
- RequestLen += (OpLen + 4);
+ RequestOpt += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
+ RequestLen += (OpLen + PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN);
}
Status = PxeBc->UdpWrite (
diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.h b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.h index c86f6d391b..6357d27fae 100644 --- a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.h +++ b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.h @@ -34,6 +34,23 @@ #define PXEBC_ADDR_START_DELIMITER '['
#define PXEBC_ADDR_END_DELIMITER ']'
+//
+// A DUID consists of a 2-octet type code represented in network byte
+// order, followed by a variable number of octets that make up the
+// actual identifier. The length of the DUID (not including the type
+// code) is at least 1 octet and at most 128 octets.
+//
+#define PXEBC_MIN_SIZE_OF_DUID (sizeof(UINT16) + 1)
+#define PXEBC_MAX_SIZE_OF_DUID (sizeof(UINT16) + 128)
+
+//
+// This define represents the combineds code and length field from
+// https://datatracker.ietf.org/doc/html/rfc3315#section-22.1
+//
+#define PXEBC_COMBINED_SIZE_OF_OPT_CODE_AND_LEN \
+ (sizeof (((EFI_DHCP6_PACKET_OPTION *)0)->OpCode) + \
+ sizeof (((EFI_DHCP6_PACKET_OPTION *)0)->OpLen))
+
#define GET_NEXT_DHCP6_OPTION(Opt) \
(EFI_DHCP6_PACKET_OPTION *) ((UINT8 *) (Opt) + \
sizeof (EFI_DHCP6_PACKET_OPTION) + (NTOHS ((Opt)->OpLen)) - 1)
|