}
struct variable_validate {
+ efi_guid_t vendor;
char *name;
bool (*validate)(efi_char16_t *var_name, int match, u8 *data,
unsigned long len);
};
+/*
+ * This is the list of variables we need to validate, as well as the
+ * whitelist for what we think is safe not to default to immutable.
+ *
+ * If it has a validate() method that's not NULL, it'll go into the
+ * validation routine. If not, it is assumed valid, but still used for
+ * whitelisting.
+ *
+ * Note that it's sorted by {vendor,name}, but globbed names must come after
+ * any other name with the same prefix.
+ */
static const struct variable_validate variable_validate[] = {
- { "BootNext", validate_uint16 },
- { "BootOrder", validate_boot_order },
- { "DriverOrder", validate_boot_order },
- { "Boot*", validate_load_option },
- { "Driver*", validate_load_option },
- { "ConIn", validate_device_path },
- { "ConInDev", validate_device_path },
- { "ConOut", validate_device_path },
- { "ConOutDev", validate_device_path },
- { "ErrOut", validate_device_path },
- { "ErrOutDev", validate_device_path },
- { "Timeout", validate_uint16 },
- { "Lang", validate_ascii_string },
- { "PlatformLang", validate_ascii_string },
- { "", NULL },
+ { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 },
+ { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order },
+ { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option },
+ { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order },
+ { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path },
+ { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string },
+ { EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL },
+ { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string },
+ { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 },
+ { LINUX_EFI_CRASH_GUID, "*", NULL },
+ { NULL_GUID, "", NULL },
};
+/*
+ * Check if @var_name matches the pattern given in @match_name.
+ *
+ * @var_name: an array of @len non-NUL characters.
+ * @match_name: a NUL-terminated pattern string, optionally ending in "*". A
+ * final "*" character matches any trailing characters @var_name,
+ * including the case when there are none left in @var_name.
+ * @match: on output, the number of non-wildcard characters in @match_name
+ * that @var_name matches, regardless of the return value.
+ * @return: whether @var_name fully matches @match_name.
+ */
+static bool
+variable_matches(const char *var_name, size_t len, const char *match_name,
+ int *match)
+{
+ for (*match = 0; ; (*match)++) {
+ char c = match_name[*match];
+
+ switch (c) {
+ case '*':
+ /* Wildcard in @match_name means we've matched. */
+ return true;
+
+ case '\0':
+ /* @match_name has ended. Has @var_name too? */
+ return (*match == len);
+
+ default:
+ /*
+ * We've reached a non-wildcard char in @match_name.
+ * Continue only if there's an identical character in
+ * @var_name.
+ */
+ if (*match < len && c == var_name[*match])
+ continue;
+ return false;
+ }
+ }
+}
+
bool
-efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len)
+efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
+ unsigned long data_size)
{
int i;
- u16 *unicode_name = var_name;
+ unsigned long utf8_size;
+ u8 *utf8_name;
- for (i = 0; variable_validate[i].validate != NULL; i++) {
- const char *name = variable_validate[i].name;
- int match;
+ utf8_size = ucs2_utf8size(var_name);
+ utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL);
+ if (!utf8_name)
+ return false;
- for (match = 0; ; match++) {
- char c = name[match];
- u16 u = unicode_name[match];
+ ucs2_as_utf8(utf8_name, var_name, utf8_size);
+ utf8_name[utf8_size] = '\0';
- /* All special variables are plain ascii */
- if (u > 127)
- return true;
+ for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
+ const char *name = variable_validate[i].name;
+ int match = 0;
- /* Wildcard in the matching name means we've matched */
- if (c == '*')
- return variable_validate[i].validate(var_name,
- match, data, len);
+ if (efi_guidcmp(vendor, variable_validate[i].vendor))
+ continue;
- /* Case sensitive match */
- if (c != u)
+ if (variable_matches(utf8_name, utf8_size+1, name, &match)) {
+ if (variable_validate[i].validate == NULL)
break;
-
- /* Reached the end of the string while matching */
- if (!c)
- return variable_validate[i].validate(var_name,
- match, data, len);
+ kfree(utf8_name);
+ return variable_validate[i].validate(var_name, match,
+ data, data_size);
}
}
-
+ kfree(utf8_name);
return true;
}
EXPORT_SYMBOL_GPL(efivar_validate);
+bool
+efivar_variable_is_removable(efi_guid_t vendor, const char *var_name,
+ size_t len)
+{
+ int i;
+ bool found = false;
+ int match = 0;
+
+ /*
+ * Check if our variable is in the validated variables list
+ */
+ for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
+ if (efi_guidcmp(variable_validate[i].vendor, vendor))
+ continue;
+
+ if (variable_matches(var_name, len,
+ variable_validate[i].name, &match)) {
+ found = true;
+ break;
+ }
+ }
+
+ /*
+ * If it's in our list, it is removable.
+ */
+ return found;
+}
+EXPORT_SYMBOL_GPL(efivar_variable_is_removable);
+
static efi_status_t
check_var_size(u32 attributes, unsigned long size)
{
*set = false;
- if (efivar_validate(name, data, *size) == false)
+ if (efivar_validate(*vendor, name, data, *size) == false)
return -EINVAL;
/*
projects / firefly-linux-kernel-4.4.55.git / blobdiff