ACK: [PATCH] uefirtvariable: fix decalred VLA have zero size (LP: #1526815)

[Alex Hung]

On 12/17/2015 04:11 PM, Ivan Hu wrote:
> Static analysis from clang scan-build found a declared variable-length
> array(VLA) has zero size, setvariable_insertvariable() declares data[datasize],
> however, it is called when delete a variable as follows:
> ret = setvariable_insertvariable(fw, attributes, 0, variablenametest,
> &gtestguid1, datadiff);
> so got a declared data[0] declared.
>
> Signed-off-by: Ivan Hu <ivan.hu at canonical.com>
> ---
>   src/uefi/uefirtvariable/uefirtvariable.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/src/uefi/uefirtvariable/uefirtvariable.c b/src/uefi/uefirtvariable/uefirtvariable.c
> index b3c7559..27aa9a1 100644
> --- a/src/uefi/uefirtvariable/uefirtvariable.c
> +++ b/src/uefi/uefirtvariable/uefirtvariable.c
> @@ -867,7 +867,11 @@ static int setvariable_insertvariable(
>   	uint64_t status;
>   	uint64_t dataindex;
>
> -	uint8_t data[datasize];
> +	uint8_t *data = malloc (datasize);
> +	if ((datasize != 0) && !data) {
> +		fwts_skipped(fw, "Unable to alloc memory for data");
> +		return FWTS_SKIP;
> +	}
>
>   	for (dataindex = 0; dataindex < datasize; dataindex++)
>   		data[dataindex] = (uint8_t)dataindex + datadiff;
> @@ -892,6 +896,8 @@ static int setvariable_insertvariable(
>   				"with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS or "
>   				"EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS "
>   				"EFI_VARIABLE_APPEND_WRITE attributes is set.");
> +			if (data)
> +				free(data);
>   			return FWTS_SKIP;
>   		}
>   		if (datasize == 0)
> @@ -910,6 +916,8 @@ static int setvariable_insertvariable(
>   					"after rebooting. Reboot and test "
>   					"again may be helpful to continue "
>   					"the test.");
> +				if (data)
> +					free(data);
>   				return FWTS_SKIP;
>   			}
>   			fwts_failed(fw, LOG_LEVEL_HIGH,
> @@ -918,8 +926,13 @@ static int setvariable_insertvariable(
>   				"runtime service.");
>   		}
>   		fwts_uefi_print_status_info(fw, status);
> +		if (data)
> +			free(data);
>   		return FWTS_ERROR;
>   	}
> +
> +	if (data)
> +		free(data);
>   	return FWTS_OK;
>   }
>
>

Acked-by: Alex Hung <alex.hung at canonical.com>