efi: Do variable name validation tests in utf8

Actually translate from ucs2 to utf8 before doing the test, and then
test against our other utf8 data, instead of fudging it.

Signed-off-by: Peter Jones <pjones@redhat.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

1 files changed, 21 insertions, 11 deletions

diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 70a0fb10517f..5c5fde3e6c37 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -189,10 +189,19 @@ static const struct variable_validate variable_validate[] = {
 };
 
 bool
-efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len)
+efivar_validate(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;
+
+        utf8_size = ucs2_utf8size(var_name);
+        utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL);
+        if (!utf8_name)
+                return false;
+
+        ucs2_as_utf8(utf8_name, var_name, utf8_size);
+        utf8_name[utf8_size] = '\0';
 
         for (i = 0; variable_validate[i].validate != NULL; i++) {
                 const char *name = variable_validate[i].name;
@@ -200,28 +209,29 @@ efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len)
 
                 for (match = 0; ; match++) {
                         char c = name[match];
-                        u16 u = unicode_name[match];
-
-                        /* All special variables are plain ascii */
-                        if (u > 127)
-                                return true;
+                        char u = utf8_name[match];
 
                         /* Wildcard in the matching name means we've matched */
-                        if (c == '*')
+                        if (c == '*') {
+                                kfree(utf8_name);
                                 return variable_validate[i].validate(var_name,
-                                                             match, data, len);
+                                                        match, data, data_size);
+                        }
 
                         /* Case sensitive match */
                         if (c != u)
                                 break;
 
                         /* Reached the end of the string while matching */
-                        if (!c)
+                        if (!c) {
+                                kfree(utf8_name);
                                 return variable_validate[i].validate(var_name,
-                                                             match, data, len);
+                                                        match, data, data_size);
+                        }
                 }
         }
 
+        kfree(utf8_name);
         return true;
 }
 EXPORT_SYMBOL_GPL(efivar_validate);