static bool
validate_load_option(struct efi_variable *var, int match, u8 *buffer,
unsigned long len)
{
u16 filepathlength;
int i, desclength = 0, namelen;
namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
/* Either "Boot" or "Driver" followed by four digits of hex */
for (i = match; i < match+4; i++) {
if (var->VariableName[i] > 127 ||
hex_to_bin(var->VariableName[i] & 0xff) < 0)
return true;
}
/* Reject it if there's 4 digits of hex and then further content */
if (namelen > match + 4)
return false;
/* A valid entry must be at least 8 bytes */
if (len < 8)
return false;
filepathlength = buffer[4] | buffer[5] << 8;
/*
* There's no stored length for the description, so it has to be
* found by hand
*/
desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
/* Each boot entry must have a descriptor */
if (!desclength)
return false;
/*
* If the sum of the length of the description, the claimed filepath
* length and the original header are greater than the length of the
* variable, it's malformed
*/
if ((desclength + filepathlength + 6) > len)
return false;
/*
* And, finally, check the filepath
*/
return validate_device_path(var, match, buffer + desclength + 6,
filepathlength);
}
static bool
validate_load_option(struct efi_variable *var, int match, u8 *buffer,
unsigned long len)
{
u16 filepathlength;
int i, desclength = 0, namelen;
namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
for (i = match; i < match+4; i++) {
if (var->VariableName[i] > 127 ||
hex_to_bin(var->VariableName[i] & 0xff) < 0)
return true;
}
if (namelen > match + 4)
return false;
if (len < 8)
return false;
filepathlength = buffer[4] | buffer[5] << 8;
desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
if (!desclength)
return false;
if ((desclength + filepathlength + 6) > len)
return false;
return validate_device_path(var, match, buffer + desclength + 6,
filepathlength);
}
/*
* Return the number of bytes is the length of this string
* Note: this is NOT the same as the number of unicode characters
*/
static inline unsigned long
utf16_strsize(efi_char16_t *data, unsigned long maxlength)
{
return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
}
static inline unsigned long
utf16_strlen(efi_char16_t *s)
{
return utf16_strnlen(s, ~0UL);
}
