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[2] [2] [2] FreeRTOS_DHCP_utest: Fix systematic memory errors in test…
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… input

The trivial problem: Screenfuls of misaligned store warnings:

    Store to misaligned address 0x7ffe* for type 'uint32_t',
    which requires 4 byte alignment

I assume there is no reason not to convert these to memcpy.
I have done that when that was the only problem I saw.

The more involved problem: The length fields, buffer sizes and
stop byte (0xFF) offsets have fallen out of maintenance.
This would lead the DHCP option parser under test to read out
of bounds when it overshot the stop byte. Symptom:

    AddressSanitizer: dynamic-stack-buffer-overflow on address 0x7ffc9dfa5c07
    READ of size 1 at 0x7ffc9dfa5c07 thread T0
    #0 0x459a49 in prvProcessDHCPReplies test/unit-test/build/Annexed_TCP_Sources/FreeRTOS_DHCP.c:1310
    FreeRTOS#1 0x4526d2 in vHandleWaitingAcknowledge test/unit-test/build/Annexed_TCP_Sources/FreeRTOS_DHCP.c:495
    FreeRTOS#2 0x4544ef in vDHCPProcessEndPoint test/unit-test/build/Annexed_TCP_Sources/FreeRTOS_DHCP.c:739
    FreeRTOS#3 0x43dbd9 in test_vDHCPProcess_eWaitingAcknowledge_DNSIncorrectLength2
        (test/unit-test/build/bin/tests/FreeRTOS_DHCP_utest+0x43dbd9)

    Address 0x7ffc9dfa5c07 is located in stack of thread T0
    SUMMARY: AddressSanitizer: dynamic-stack-buffer-overflow
        test/unit-test/build/Annexed_TCP_Sources/FreeRTOS_DHCP.c:1310 in prvProcessDHCPReplies
    Shadow bytes around the buggy address:
    0x7ffc9dfa5980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5a80: 00 00 00 00 00 00 00 00 ca ca ca ca 00 00 00 00
    0x7ffc9dfa5b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    =>0x7ffc9dfa5c00:[05]cb cb cb cb cb cb cb 00 00 00 00 00 00 00 00
    0x7ffc9dfa5c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x7ffc9dfa5e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Left alloca redzone:   ca
    Right alloca redzone:  cb

I think this calls for some helper functions, which I've added.
These eliminate the possibility for such inconsistencies,
drastically cuts down on low-entropy code,
and by wrapping memcpy, also avoids the first problem.
I have done that instead wherever I also saw this kind of inconsistencies.
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@anordal
anordal committed May 26, 2024
1 parent 8ae475e commit ab9617a
Showing 1 changed file with 50 additions and 101 deletions.
151 changes: 50 additions & 101 deletions test/unit-test/FreeRTOS_DHCP/FreeRTOS_DHCP_utest.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,38 @@ extern uint8_t pucUDPBuffer[];

extern uint8_t DHCP_header[];

/*-------------------------------------Helpers--------------------------------*/

static void prvWriteDHCPOption( uint8_t ** ppucBuf,
uint8_t ucOp,
const void * pvPayload,
uint8_t ucLen )
{
uint8_t * pucBuf = *ppucBuf;

*pucBuf++ = ucOp;
*pucBuf++ = ucLen;
memcpy( pucBuf, pvPayload, ucLen );
pucBuf += ucLen;

*ppucBuf = pucBuf;
}

static void prvWriteDHCPOptionU8( uint8_t ** ppucBuf,
uint8_t ucOp,
uint8_t ucPayload )
{
prvWriteDHCPOption( ppucBuf, ucOp, &ucPayload, sizeof( ucPayload ) );
}

static void prvWriteDHCPOptionU32( uint8_t ** ppucBuf,
uint8_t ucOp,
uint32_t ulPayload )
{
/* TBD: htonl(ulPayload)? */
prvWriteDHCPOption( ppucBuf, ucOp, &ulPayload, sizeof( ulPayload ) );
}

/*---------------------------------------Test Cases--------------------------*/
void test_xIsDHCPSocket( void )
{
Expand Down Expand Up @@ -4538,9 +4570,6 @@ void test_vDHCPProcess_eWaitingAcknowledge_IncorrectDNSServerAddress( void )
NetworkEndPoint_t xEndPoint = { 0 }, * pxEndPoint = &xEndPoint;
IPV4Parameters_t * xIPv4Addressing = &( pxEndPoint->ipv4_settings );

DHCPMsg[ xTotalLength - 1U ] = 0xFF;


/* Set the header - or at least the start of DHCP message. */
memset( DHCPMsg, 0, sizeof( DHCPMsg ) );
/* Copy the header here. */
Expand All @@ -4556,53 +4585,16 @@ void test_vDHCPProcess_eWaitingAcknowledge_IncorrectDNSServerAddress( void )

/* Leave one byte for the padding. */
uint8_t * DHCPOption = &DHCPMsg[ sizeof( struct xDHCPMessage_IPv4 ) + 1 ];
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_MESSAGE_TYPE_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 1;
/* Add the offer byte. */
DHCPOption[ 2 ] = dhcpMESSAGE_TYPE_ACK;

DHCPOption += 4;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = DHCPServerAddress;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_SUBNET_MASK_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ulSubnetMask;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_GATEWAY_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ulGateway;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_LEASE_TIME_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ulLeaseTime;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_DNS_SERVER_OPTIONS_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = FREERTOS_INADDR_ANY;
prvWriteDHCPOptionU8( &DHCPOption, dhcpIPv4_MESSAGE_TYPE_OPTION_CODE, dhcpMESSAGE_TYPE_ACK );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE, DHCPServerAddress );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_SUBNET_MASK_OPTION_CODE, ulSubnetMask );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_GATEWAY_OPTION_CODE, ulGateway );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_LEASE_TIME_OPTION_CODE, ulLeaseTime );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_DNS_SERVER_OPTIONS_CODE, FREERTOS_INADDR_ANY );

*DHCPOption++ = 0xFF;
TEST_ASSERT_EQUAL( DHCPOption - DHCPMsg, xTotalLength );

/* Put the information in global variables to be returned by
* the FreeRTOS_recvrom. */
Expand Down Expand Up @@ -4684,9 +4676,6 @@ void test_vDHCPProcess_eWaitingAcknowledge_IncorrectDNSServerAddress2( void )
NetworkEndPoint_t xEndPoint = { 0 }, * pxEndPoint = &xEndPoint;
IPV4Parameters_t * xIPv4Addressing = &( pxEndPoint->ipv4_settings );

DHCPMsg[ xTotalLength - 1U ] = 0xFF;


/* Set the header - or at least the start of DHCP message. */
memset( DHCPMsg, 0, sizeof( DHCPMsg ) );
/* Copy the header here. */
Expand All @@ -4702,53 +4691,16 @@ void test_vDHCPProcess_eWaitingAcknowledge_IncorrectDNSServerAddress2( void )

/* Leave one byte for the padding. */
uint8_t * DHCPOption = &DHCPMsg[ sizeof( struct xDHCPMessage_IPv4 ) + 1 ];
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_MESSAGE_TYPE_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 1;
/* Add the offer byte. */
DHCPOption[ 2 ] = dhcpMESSAGE_TYPE_ACK;

DHCPOption += 4;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = DHCPServerAddress;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_SUBNET_MASK_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ulSubnetMask;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_GATEWAY_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ulGateway;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_LEASE_TIME_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ulLeaseTime;

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_DNS_SERVER_OPTIONS_CODE;
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = ipBROADCAST_IP_ADDRESS;
prvWriteDHCPOptionU8( &DHCPOption, dhcpIPv4_MESSAGE_TYPE_OPTION_CODE, dhcpMESSAGE_TYPE_ACK );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE, DHCPServerAddress );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_SUBNET_MASK_OPTION_CODE, ulSubnetMask );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_GATEWAY_OPTION_CODE, ulGateway );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_LEASE_TIME_OPTION_CODE, ulLeaseTime );
prvWriteDHCPOptionU32( &DHCPOption, dhcpIPv4_DNS_SERVER_OPTIONS_CODE, ipBROADCAST_IP_ADDRESS );

*DHCPOption++ = 0xFF;
TEST_ASSERT_EQUAL( DHCPOption - DHCPMsg, xTotalLength );

/* Put the information in global variables to be returned by
* the FreeRTOS_recvrom. */
Expand Down Expand Up @@ -4821,9 +4773,6 @@ void test_vDHCPProcess_eWaitingAcknowledge_IPv4ServerIncorrectLength( void )
uint8_t DHCPMsg[ xTotalLength ];
uint32_t DHCPServerAddress = 0xC0A80001; /* 192.168.0.1 */
uint32_t ulClientIPAddress = 0xC0A8000A; /* 192.168.0.10 */
uint32_t ulSubnetMask = 0xFFFFF100; /* 255.255.241.0 */
uint32_t ulGateway = 0xC0A80001; /* 192.168.0.1 */
uint32_t ulLeaseTime = 0x00000096; /* 150 seconds */
DHCPMessage_IPv4_t * pxDHCPMessage = ( DHCPMessage_IPv4_t * ) DHCPMsg;
NetworkEndPoint_t xEndPoint = { 0 }, * pxEndPoint = &xEndPoint;

Expand Down Expand Up @@ -4858,15 +4807,15 @@ void test_vDHCPProcess_eWaitingAcknowledge_IPv4ServerIncorrectLength( void )
/* Add length. */
DHCPOption[ 1 ] = 4;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = DHCPServerAddress;
memcpy( &DHCPOption[ 2 ], &DHCPServerAddress, sizeof( DHCPServerAddress ) );

DHCPOption += 6;
/* Add Message type code. */
DHCPOption[ 0 ] = dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE;
/* Add length. */
DHCPOption[ 1 ] = 3;
/* Add the offer byte. */
*( ( uint32_t * ) &DHCPOption[ 2 ] ) = DHCPServerAddress;
memcpy( &DHCPOption[ 2 ], &DHCPServerAddress, sizeof( DHCPServerAddress ) );

/* Put the information in global variables to be returned by
* the FreeRTOS_recvrom. */
Expand Down

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