efi_loader: variable: attributes may not be changed if a variable exists
If a variable already exists, efi_set_variable() should not change
the variable's attributes. This patch enforces it.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 0d97377..50bc105 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -451,12 +451,21 @@
if (val) {
parse_attr(val, &attr);
+ /* We should not free val */
+ val = NULL;
if (attr & READ_ONLY) {
- /* We should not free val */
- val = NULL;
ret = EFI_WRITE_PROTECTED;
goto out;
}
+
+ /*
+ * attributes won't be changed
+ * TODO: take care of APPEND_WRITE once supported
+ */
+ if (attr != attributes) {
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
}
val = malloc(2 * data_size + strlen("{ro,run,boot}(blob)") + 1);