efi_loader: only check size if EFI_DT_APPLY_FIXUPS
In the implementation of the EFI_DT_FIXUP_PROTOCOL:
* Only check the buffer size when EFI_DT_APPLY_FIXUPS is set.
* In this case the field totalsize of the device-tree may not exceed the
buffer size.
* Install device-tree only if EFI_DT_INSTALL_TABLE is set.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/efi_dt_fixup.c b/lib/efi_loader/efi_dt_fixup.c
index 3850ab3..6de57b8 100644
--- a/lib/efi_loader/efi_dt_fixup.c
+++ b/lib/efi_loader/efi_dt_fixup.c
@@ -110,6 +110,7 @@
{
efi_status_t ret;
size_t required_size;
+ size_t total_size;
bootm_headers_t img = { 0 };
EFI_ENTRY("%p, %p, %p, %d", this, dtb, buffer_size, flags);
@@ -124,20 +125,20 @@
goto out;
}
if (flags & EFI_DT_APPLY_FIXUPS) {
+ /* Check size */
required_size = fdt_off_dt_strings(dtb) +
fdt_size_dt_strings(dtb) +
0x3000;
- } else {
- required_size = fdt_totalsize(dtb);
- }
- if (required_size > *buffer_size) {
- *buffer_size = required_size;
- ret = EFI_BUFFER_TOO_SMALL;
- goto out;
- }
- fdt_set_totalsize(dtb, *buffer_size);
+ total_size = fdt_totalsize(dtb);
+ if (required_size < total_size)
+ required_size = total_size;
+ if (required_size > *buffer_size) {
+ *buffer_size = required_size;
+ ret = EFI_BUFFER_TOO_SMALL;
+ goto out;
+ }
- if (flags & EFI_DT_APPLY_FIXUPS) {
+ fdt_set_totalsize(dtb, *buffer_size);
if (image_setup_libfdt(&img, dtb, 0, NULL)) {
log_err("failed to process device tree\n");
ret = EFI_INVALID_PARAMETER;
@@ -147,10 +148,10 @@
if (flags & EFI_DT_RESERVE_MEMORY)
efi_carve_out_dt_rsv(dtb);
- if (EFI_DT_INSTALL_TABLE) {
+ if (flags & EFI_DT_INSTALL_TABLE) {
ret = efi_install_configuration_table(&efi_guid_fdt, dtb);
if (ret != EFI_SUCCESS) {
- log_err("ERROR: failed to install device tree\n");
+ log_err("failed to install device tree\n");
goto out;
}
}