ACK: [PATCH][V2] dmicheck: checks type length vs. SMBIOS versions

[Colin Ian King]

On 26/04/2019 01:54, Alex Hung wrote:
> Buglink: https://bugs.launchpad.net/bugs/1824397
> 
> Some SMBIOS types grow with SMBIOS specs. This checks whether BIOS
> implements new SMBIOS spec accordingly.
> 
> Signed-off-by: Alex Hung <alex.hung at canonical.com>
> ---
>  src/dmi/dmicheck/dmicheck.c | 90 +++++++++++++++++++++++++++++++++++--
>  1 file changed, 87 insertions(+), 3 deletions(-)
> 
> diff --git a/src/dmi/dmicheck/dmicheck.c b/src/dmi/dmicheck/dmicheck.c
> index a5b88187..f2d1271e 100644
> --- a/src/dmi/dmicheck/dmicheck.c
> +++ b/src/dmi/dmicheck/dmicheck.c
> @@ -83,6 +83,13 @@ typedef struct {
>  	uint8_t	offset;
>  } fwts_dmi_used_by_kernel;
>  
> +typedef struct {
> +	uint8_t type;
> +	uint16_t max_version;
> +	uint16_t min_version;
> +	uint8_t length;
> +} fwts_dmi_type_length;
> +
>  static bool smbios_found = false;
>  static bool smbios30_found = false;
>  
> @@ -261,6 +268,25 @@ static const fwts_dmi_used_by_kernel dmi_used_by_kernel_table[] = {
>  	{ TYPE_EOD, 0xff },
>  };
>  
> +#define MAX_VERSION	0xFFFF
> +
> +static const fwts_dmi_type_length type_info[] = {
> +	/* type, max_version, min_version, length */
> +	{ 15, 0x201, 0x200, 0x14 },
> +	{ 16, 0x207, 0x201, 0xf },
> +	{ 16, MAX_VERSION, 0x207, 0x17 },
> +	{ 17, 0x203, 0x201, 0x15 },
> +	{ 17, 0x206, 0x203, 0x1b },
> +	{ 17, 0x207, 0x206, 0x1c },
> +	{ 17, 0x208, 0x207, 0x22 },
> +	{ 17, 0x302, 0x208, 0x28 },
> +	{ 19, 0x207, 0x201, 0xf },
> +	{ 19, MAX_VERSION, 0x207, 0x1f },
> +	{ 20, 0x207, 0x201, 0x13 },
> +	{ 20, MAX_VERSION, 0x207, 0x23 },
> +	{ 0, 0, 0, 0 } /* terminator */
> +};
> +
>  static int dmi_load_file(const char* filename, void *buf, size_t size)
>  {
>  	int fd;
> @@ -1113,9 +1139,61 @@ static void dmi_uuid_check(fwts_framework *fw,
>  	}
>  }
>  
> +static void dmicheck_type_length(
> +	fwts_framework *fw,
> +	const uint16_t smbios_version,
> +	const fwts_dmi_header *hdr)
> +{
> +	const fwts_dmi_type_length *tbl = type_info;
> +	const uint8_t *data = hdr->data;
> +	uint8_t length = hdr->length;
> +	bool passed = false;
> +
> +	/* Special cases */
> +	switch (hdr->type) {
> +		case 15:
> +			if (smbios_version >= 0x201 && length >= 17) {
> +				length = 0x17 + data[0x15] * data[0x16];
> +				if (length == hdr->length)
> +					passed = true;
> +			}
> +			break;
> +		case 17:
> +			if (smbios_version >= 0x302 && length >= 0x34)
> +				passed = true;
> +			break;
> +		default:
> +			passed = true;
> +			break;
> +	}
> +
> +	/* general cases */
> +	while (tbl->length != 0) {
> +		if (hdr->type != tbl->type) {
> +				tbl++;
> +				continue;
> +		}
> +		if (smbios_version >= tbl->min_version && smbios_version < tbl->max_version) {
> +			if (length == tbl->length) {
> +				passed = true;
> +			} else
> +				passed = false;
> +			break;
> +		}
> +		tbl++;
> +	}
> +
> +	if (!passed)
> +		fwts_failed(fw, LOG_LEVEL_HIGH, DMI_BAD_TABLE_LENGTH,
> +			"Type %" PRId8 " expects length of 0x%" PRIx8
> +			", has incorrect length of 0x%" PRIx8,
> +			hdr->type, tbl->length, length);
> +}
> +
>  static void dmicheck_entry(fwts_framework *fw,
>  	uint32_t addr,
> -	const fwts_dmi_header *hdr)
> +	const fwts_dmi_header *hdr,
> +	const uint16_t smbios_version)
>  {
>  	uint8_t *ptr;
>  	uint8_t count;
> @@ -1129,6 +1207,8 @@ static void dmicheck_entry(fwts_framework *fw,
>  	uint32_t battery_count;
>  	int	ret;
>  
> +	dmicheck_type_length(fw, smbios_version, hdr);
> +
>  	switch (hdr->type) {
>  		case 0: /* 7.1 */
>  			table = "BIOS Information (Type 0)";
> @@ -1892,6 +1972,8 @@ static void dmi_scan_tables(fwts_framework *fw,
>  	fwts_smbios_entry *entry,
>  	uint8_t  *table)
>  {
> +	const uint16_t smbios_version = (entry->major_version << 8) +
> +					entry->minor_version;
>  	uint8_t *entry_data = table;
>  	uint16_t table_length;
>  	uint16_t struct_count;
> @@ -1937,7 +2019,7 @@ static void dmi_scan_tables(fwts_framework *fw,
>  		next_entry += 2;
>  
>  		if ((next_entry - table) <= table_length)
> -			dmicheck_entry(fw, addr, &hdr);
> +			dmicheck_entry(fw, addr, &hdr, smbios_version);
>  
>  		i++;
>  		entry_data = next_entry;
> @@ -2008,6 +2090,8 @@ static void dmi_scan_smbios30_table(fwts_framework *fw,
>  	fwts_smbios30_entry *entry,
>  	uint8_t  *table)
>  {
> +	const uint16_t smbios_version = (entry->major_version << 8) +
> +					entry->minor_version;
>  	uint8_t *entry_data = table;
>  	uint16_t table_max_length;
>  	int i = 0;
> @@ -2054,7 +2138,7 @@ static void dmi_scan_smbios30_table(fwts_framework *fw,
>  		next_entry += 2;
>  
>  		if ((next_entry - table) <= table_max_length) {
> -			dmicheck_entry(fw, addr, &hdr);
> +			dmicheck_entry(fw, addr, &hdr, smbios_version);
>  			if (fw->flags & FWTS_FLAG_TEST_SBBR)
>  				sbbr_test_entry_check(&hdr);
>  		}
> 

Thanks Alex.

Acked-by: Colin Ian King <colin.king at canonical.com>