From 806165285b822436023df84ca0a3e5b28a3099d6 Mon Sep 17 00:00:00 2001 From: Jan Janssen Date: Mon, 14 Nov 2022 15:24:32 +0100 Subject: [PATCH] boot: Manually convert filepaths if needed The conversion of a filepath device path to text is needed for the stub loader to find credential files. (cherry picked from commit 679007044fbbcf82c66cf20b99f2f5086b7df6b4) Related: #2138081 --- src/boot/efi/util.c | 40 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/src/boot/efi/util.c b/src/boot/efi/util.c index 5547d288de..57436dbf0c 100644 --- a/src/boot/efi/util.c +++ b/src/boot/efi/util.c @@ -772,19 +772,51 @@ EFI_STATUS make_file_device_path(EFI_HANDLE device, const char16_t *file, EFI_DE EFI_STATUS device_path_to_str(const EFI_DEVICE_PATH *dp, char16_t **ret) { EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *dp_to_text; EFI_STATUS err; + _cleanup_free_ char16_t *str = NULL; assert(dp); assert(ret); err = BS->LocateProtocol(&(EFI_GUID) EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID, NULL, (void **) &dp_to_text); - if (err != EFI_SUCCESS) - return err; + if (err != EFI_SUCCESS) { + /* If the device path to text protocol is not available we can still do a best-effort attempt + * to convert it ourselves if we are given filepath-only device path. */ + + size_t size = 0; + for (const EFI_DEVICE_PATH *node = dp; !IsDevicePathEnd(node); + node = NextDevicePathNode(node)) { + + if (DevicePathType(node) != MEDIA_DEVICE_PATH || + DevicePathSubType(node) != MEDIA_FILEPATH_DP) + return err; + + size_t path_size = DevicePathNodeLength(node); + if (path_size <= offsetof(FILEPATH_DEVICE_PATH, PathName) || path_size % sizeof(char16_t)) + return EFI_INVALID_PARAMETER; + path_size -= offsetof(FILEPATH_DEVICE_PATH, PathName); + + _cleanup_free_ char16_t *old = str; + str = xmalloc(size + path_size); + if (old) { + memcpy(str, old, size); + str[size / sizeof(char16_t) - 1] = '\\'; + } + + memcpy(str + (size / sizeof(char16_t)), + ((uint8_t *) node) + offsetof(FILEPATH_DEVICE_PATH, PathName), + path_size); + size += path_size; + } + + *ret = TAKE_PTR(str); + return EFI_SUCCESS; + } - char16_t *str = dp_to_text->ConvertDevicePathToText(dp, false, false); + str = dp_to_text->ConvertDevicePathToText(dp, false, false); if (!str) return EFI_OUT_OF_RESOURCES; - *ret = str; + *ret = TAKE_PTR(str); return EFI_SUCCESS; }