efi_loader: remove limit on variable length

The EFI spec does not provide a length limit for variables.

Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 770c67abb98035250661d3378b71b24fcb511a00..495738884b8a6fc9b401bc4592374aa882e1e3d4 100644 (file)
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -44,10 +44,7 @@
  * converted to utf16?
  */
 
-#define MAX_VAR_NAME 31
-#define MAX_NATIVE_VAR_NAME \
-       (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx_") + \
-               (MAX_VAR_NAME * MAX_UTF8_PER_UTF16))
+#define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx_"))
 
 static int hex(int ch)
 {
@@ -101,18 +98,20 @@ static char *mem2hex(char *hexstr, const u8 *mem, int count)
        return hexstr;
 }
 
-static efi_status_t efi_to_native(char *native, u16 *variable_name,
+static efi_status_t efi_to_native(char **native, const u16 *variable_name,
                                  efi_guid_t *vendor)
 {
        size_t len;
+       char *pos;
 
-       len = u16_strlen((u16 *)variable_name);
-       if (len >= MAX_VAR_NAME)
-               return EFI_DEVICE_ERROR;
+       len = PREFIX_LEN + utf16_utf8_strlen(variable_name) + 1;
+       *native = malloc(len);
+       if (!*native)
+               return EFI_OUT_OF_RESOURCES;
 
-       native += sprintf(native, "efi_%pUl_", vendor);
-       native  = (char *)utf16_to_utf8((u8 *)native, (u16 *)variable_name, len);
-       *native = '\0';
+       pos = *native;
+       pos += sprintf(pos, "efi_%pUl_", vendor);
+       utf16_utf8_strcpy(&pos, variable_name);
 
        return EFI_SUCCESS;
 }
@@ -168,7 +167,7 @@ efi_status_t EFIAPI efi_get_variable(u16 *variable_name, efi_guid_t *vendor,
                                     u32 *attributes, efi_uintn_t *data_size,
                                     void *data)
 {
-       char native_name[MAX_NATIVE_VAR_NAME + 1];
+       char *native_name;
        efi_status_t ret;
        unsigned long in_size;
        const char *val, *s;
@@ -180,13 +179,14 @@ efi_status_t EFIAPI efi_get_variable(u16 *variable_name, efi_guid_t *vendor,
        if (!variable_name || !vendor || !data_size)
                return EFI_EXIT(EFI_INVALID_PARAMETER);
 
-       ret = efi_to_native(native_name, variable_name, vendor);
+       ret = efi_to_native(&native_name, variable_name, vendor);
        if (ret)
                return EFI_EXIT(ret);
 
        debug("%s: get '%s'\n", __func__, native_name);
 
        val = env_get(native_name);
+       free(native_name);
        if (!val)
                return EFI_EXIT(EFI_NOT_FOUND);
 
@@ -256,35 +256,41 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor,
                                     u32 attributes, efi_uintn_t data_size,
                                     void *data)
 {
-       char native_name[MAX_NATIVE_VAR_NAME + 1];
+       char *native_name = NULL, *val = NULL, *s;
        efi_status_t ret = EFI_SUCCESS;
-       char *val, *s;
        u32 attr;
 
        EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
                  data_size, data);
 
-       if (!variable_name || !vendor)
-               return EFI_EXIT(EFI_INVALID_PARAMETER);
+       if (!variable_name || !vendor) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
 
-       ret = efi_to_native(native_name, variable_name, vendor);
+       ret = efi_to_native(&native_name, variable_name, vendor);
        if (ret)
-               return EFI_EXIT(ret);
+               goto out;
 
 #define ACCESS_ATTR (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)
 
        if ((data_size == 0) || !(attributes & ACCESS_ATTR)) {
                /* delete the variable: */
                env_set(native_name, NULL);
-               return EFI_EXIT(EFI_SUCCESS);
+               ret = EFI_SUCCESS;
+               goto out;
        }
 
        val = env_get(native_name);
        if (val) {
                parse_attr(val, &attr);
 
-               if (attr & READ_ONLY)
-                       return EFI_EXIT(EFI_WRITE_PROTECTED);
+               if (attr & READ_ONLY) {
+                       /* We should not free val */
+                       val = NULL;
+                       ret = EFI_WRITE_PROTECTED;
+                       goto out;
+               }
        }
 
        val = malloc(2 * data_size + strlen("{ro,run,boot}(blob)") + 1);
@@ -320,6 +326,8 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor,
        if (env_set(native_name, val))
                ret = EFI_DEVICE_ERROR;
 
+out:
+       free(native_name);
        free(val);
 
        return EFI_EXIT(ret);