efi_loader: parameter check in GetNextVariableName()

If GetNextVariableName() is called with a non-existing combination of
VariableName and VendorGuid, return EFI_INVALID_PARAMETER.

If GetNextVariableName() is called with a string that is not zero
terminated, return EFI_INVALID_PARAMETER.

Reformat a line over 80 characters.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c
index 1d2b445..d155f25 100644 (file)
--- a/lib/efi_loader/efi_var_mem.c
+++ b/lib/efi_loader/efi_var_mem.c
@@ -304,8 +304,8 @@ efi_get_variable_mem(u16 *variable_name, const efi_guid_t *vendor, u32 *attribut
 }
 
 efi_status_t __efi_runtime
-efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_name,
-                              efi_guid_t *vendor)
+efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size,
+                              u16 *variable_name, efi_guid_t *vendor)
 {
        struct efi_var_entry *var;
        efi_uintn_t old_size;
@@ -314,7 +314,12 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_na
        if (!variable_name_size || !variable_name || !vendor)
                return EFI_INVALID_PARAMETER;
 
-       efi_var_mem_find(vendor, variable_name, &var);
+       if (u16_strnlen(variable_name, *variable_name_size) ==
+           *variable_name_size)
+               return EFI_INVALID_PARAMETER;
+
+       if (!efi_var_mem_find(vendor, variable_name, &var) && *variable_name)
+               return EFI_INVALID_PARAMETER;
 
        if (!var)
                return EFI_NOT_FOUND;