For passing the optional data of the load option to the loaded imaged protocol we need its size.
efi_deserialize_load_option() is changed to return the size of the optional data.
As a by-product we get a partial validation of the load option. Checking the length of the device path remains to be implemented.
Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- cmd/efidebug.c | 21 +++++++++++----- include/efi_loader.h | 3 ++- lib/efi_loader/efi_bootmgr.c | 48 +++++++++++++++++++++++++++++------- 3 files changed, 56 insertions(+), 16 deletions(-)
diff --git a/cmd/efidebug.c b/cmd/efidebug.c index 32430e62f0..58018f700c 100644 --- a/cmd/efidebug.c +++ b/cmd/efidebug.c @@ -694,14 +694,19 @@ static int do_efi_boot_rm(struct cmd_tbl *cmdtp, int flag, * * Decode the value of UEFI load option variable and print information. */ -static void show_efi_boot_opt_data(u16 *varname16, void *data, size_t size) +static void show_efi_boot_opt_data(u16 *varname16, void *data, size_t *size) { struct efi_load_option lo; char *label, *p; size_t label_len16, label_len; u16 *dp_str; + efi_status_t ret;
- efi_deserialize_load_option(&lo, data); + ret = efi_deserialize_load_option(&lo, data, size); + if (ret != EFI_SUCCESS) { + printf("%ls: invalid load option\n", varname16); + return; + }
label_len16 = u16_strlen(lo.label); label_len = utf16_utf8_strnlen(lo.label, label_len16); @@ -728,8 +733,7 @@ static void show_efi_boot_opt_data(u16 *varname16, void *data, size_t size)
printf(" data:\n"); print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, - lo.optional_data, size + (u8 *)data - - (u8 *)lo.optional_data, true); + lo.optional_data, *size, true); free(label); }
@@ -759,7 +763,7 @@ static void show_efi_boot_opt(u16 *varname16) &efi_global_variable_guid, NULL, &size, data)); if (ret == EFI_SUCCESS) - show_efi_boot_opt_data(varname16, data, size); + show_efi_boot_opt_data(varname16, data, &size); free(data); } } @@ -920,7 +924,12 @@ static int show_efi_boot_order(void) goto out; }
- efi_deserialize_load_option(&lo, data); + ret = efi_deserialize_load_option(&lo, data, &size); + if (ret != EFI_SUCCESS) { + printf("%ls: invalid load option\n", var_name16); + ret = CMD_RET_FAILURE; + goto out; + }
label_len16 = u16_strlen(lo.label); label_len = utf16_utf8_strnlen(lo.label, label_len16); diff --git a/include/efi_loader.h b/include/efi_loader.h index 9533df26dc..c2cae814b6 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -708,7 +708,8 @@ struct efi_load_option { const u8 *optional_data; };
-void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data); +efi_status_t efi_deserialize_load_option(struct efi_load_option *lo, u8 *data, + efi_uintn_t *size); unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data); efi_status_t efi_bootmgr_load(efi_handle_t *handle);
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c index fa65445c12..e268e9c4b8 100644 --- a/lib/efi_loader/efi_bootmgr.c +++ b/lib/efi_loader/efi_bootmgr.c @@ -38,24 +38,50 @@ static const struct efi_runtime_services *rs; * * @lo: pointer to target * @data: serialized data + * @size: size of the load option, on return size of the optional data + * Return: status code */ -void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data) +efi_status_t efi_deserialize_load_option(struct efi_load_option *lo, u8 *data, + efi_uintn_t *size) { + efi_uintn_t len; + + len = sizeof(u32); + if (*size < len + 2 * sizeof(u16)) + return EFI_INVALID_PARAMETER; lo->attributes = get_unaligned_le32(data); - data += sizeof(u32); + data += len; + *size -= len;
+ len = sizeof(u16); lo->file_path_length = get_unaligned_le16(data); - data += sizeof(u16); + data += len; + *size -= len;
- /* FIXME */ lo->label = (u16 *)data; - data += (u16_strlen(lo->label) + 1) * sizeof(u16); - - /* FIXME */ + len = u16_strnlen(lo->label, *size / sizeof(u16) - 1); + if (lo->label[len]) + return EFI_INVALID_PARAMETER; + len = (len + 1) * sizeof(u16); + if (*size < len) + return EFI_INVALID_PARAMETER; + data += len; + *size -= len; + + len = lo->file_path_length; + if (*size < len) + return EFI_INVALID_PARAMETER; lo->file_path = (struct efi_device_path *)data; - data += lo->file_path_length; + /* + * TODO: validate device path. There should be an end node within + * the indicated file_path_length. + */ + data += len; + *size -= len;
lo->optional_data = data; + + return EFI_SUCCESS; }
/** @@ -170,7 +196,11 @@ static efi_status_t try_load_entry(u16 n, efi_handle_t *handle) if (!load_option) return EFI_LOAD_ERROR;
- efi_deserialize_load_option(&lo, load_option); + ret = efi_deserialize_load_option(&lo, load_option, &size); + if (ret != EFI_SUCCESS) { + log_warning("Invalid load option for %ls\n", varname); + goto error; + }
if (lo.attributes & LOAD_OPTION_ACTIVE) { u32 attributes; -- 2.26.2