At least some versions of Dell EFI firmware pass the entire EFI_LOAD_OPTION descriptor, rather than just the OptionalData part, to the loaded image. To handle this, add a quirk to check if the options look like a valid EFI_LOAD_OPTION descriptor, and if so, use the OptionalData part as the command line. Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Reported-by: Jacobo Pantoja <jacobopantoja@xxxxxxxxx> Link: https://lore.kernel.org/linux-efi/20200907170021.GA2284449@xxxxxxxxxxxxxxxxxx/ --- .../firmware/efi/libstub/efi-stub-helper.c | 99 ++++++++++++++++++- drivers/firmware/efi/libstub/efistub.h | 31 ++++++ drivers/firmware/efi/libstub/file.c | 5 +- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index f735db55adc0..294958ff1ee6 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -238,6 +238,100 @@ efi_status_t efi_parse_options(char const *cmdline) return EFI_SUCCESS; } +/* + * The EFI_LOAD_OPTION descriptor has the following layout: + * u32 Attributes; + * u16 FilePathListLength; + * u16 Description[]; + * efi_device_path_protocol_t FilePathList[]; + * u8 OptionalData[]; + * + * This function validates and unpacks the variable-size data fields. + */ +static +bool efi_load_option_unpack(efi_load_option_unpacked_t *dest, + const efi_load_option_t *src, size_t size) +{ + + const void *pos; + u16 c; + efi_device_path_protocol_t header; + const efi_char16_t *description; + const efi_device_path_protocol_t *file_path_list; + + if (size < offsetof(efi_load_option_t, variable_data)) + return false; + pos = src->variable_data; + size -= offsetof(efi_load_option_t, variable_data); + + if ((src->attributes & ~EFI_LOAD_OPTION_MASK) != 0) + return false; + + /* Scan description. */ + description = pos; + do { + if (size < sizeof(c)) + return false; + c = *(const u16 *)pos; + pos += sizeof(c); + size -= sizeof(c); + } while (c != L'\0'); + + /* Scan file_path_list. */ + file_path_list = pos; + do { + if (size < sizeof(header)) + return false; + header = *(const efi_device_path_protocol_t *)pos; + if (header.length < sizeof(header)) + return false; + if (size < header.length) + return false; + pos += header.length; + size -= header.length; + } while ((header.type != EFI_DEV_END_PATH && header.type != EFI_DEV_END_PATH2) || + (header.sub_type != EFI_DEV_END_ENTIRE)); + if (pos != (const void *)file_path_list + src->file_path_list_length) + return false; + + dest->attributes = src->attributes; + dest->file_path_list_length = src->file_path_list_length; + dest->description = description; + dest->file_path_list = file_path_list; + dest->optional_data_size = size; + dest->optional_data = size ? pos : NULL; + + return true; +} + +/* + * At least some versions of Dell firmware pass the entire contents of the + * Boot#### variable, i.e. the EFI_LOAD_OPTION descriptor, rather than just the + * OptionalData field. + * + * Detect this case and extract OptionalData. + */ +void efi_apply_loadoptions_quirk(const void **load_options, int *load_options_size) +{ + const efi_load_option_t *load_option = *load_options; + efi_load_option_unpacked_t load_option_unpacked; + + if (!IS_ENABLED(CONFIG_X86)) + return; + if (!load_option) + return; + if (*load_options_size < sizeof(*load_option)) + return; + if ((load_option->attributes & ~EFI_LOAD_OPTION_BOOT_MASK) != 0) + return; + + if (!efi_load_option_unpack(&load_option_unpacked, load_option, *load_options_size)) + return; + + *load_options = load_option_unpacked.optional_data; + *load_options_size = load_option_unpacked.optional_data_size; +} + /* * Convert the unicode UEFI command line to ASCII to pass to kernel. * Size of memory allocated return in *cmd_line_len. @@ -247,12 +341,15 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len) { const u16 *s2; unsigned long cmdline_addr = 0; - int options_chars = efi_table_attr(image, load_options_size) / 2; + int options_chars = efi_table_attr(image, load_options_size); const u16 *options = efi_table_attr(image, load_options); int options_bytes = 0, safe_options_bytes = 0; /* UTF-8 bytes */ bool in_quote = false; efi_status_t status; + efi_apply_loadoptions_quirk((const void **)&options, &options_chars); + options_chars /= sizeof(*options); + if (options) { s2 = options; while (options_bytes < COMMAND_LINE_SIZE && options_chars--) { diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 85050f5a1b28..589d07acb22d 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -688,6 +688,35 @@ union efi_load_file_protocol { } mixed_mode; }; +typedef struct { + u32 attributes; + u16 file_path_list_length; + u8 variable_data[]; + // efi_char16_t description[]; + // efi_device_path_protocol_t file_path_list[]; + // u8 optional_data[]; +} __packed efi_load_option_t; + +#define EFI_LOAD_OPTION_ACTIVE 0x0001U +#define EFI_LOAD_OPTION_FORCE_RECONNECT 0x0002U +#define EFI_LOAD_OPTION_HIDDEN 0x0008U +#define EFI_LOAD_OPTION_CATEGORY 0x1f00U +#define EFI_LOAD_OPTION_CATEGORY_BOOT 0x0000U +#define EFI_LOAD_OPTION_CATEGORY_APP 0x0100U + +#define EFI_LOAD_OPTION_BOOT_MASK \ + (EFI_LOAD_OPTION_ACTIVE|EFI_LOAD_OPTION_HIDDEN|EFI_LOAD_OPTION_CATEGORY) +#define EFI_LOAD_OPTION_MASK (EFI_LOAD_OPTION_FORCE_RECONNECT|EFI_LOAD_OPTION_BOOT_MASK) + +typedef struct { + u32 attributes; + u16 file_path_list_length; + const efi_char16_t *description; + const efi_device_path_protocol_t *file_path_list; + size_t optional_data_size; + const void *optional_data; +} efi_load_option_unpacked_t; + void efi_pci_disable_bridge_busmaster(void); typedef efi_status_t (*efi_exit_boot_map_processing)( @@ -730,6 +759,8 @@ __printf(1, 2) int efi_printk(char const *fmt, ...); void efi_free(unsigned long size, unsigned long addr); +void efi_apply_loadoptions_quirk(const void **load_options, int *load_options_size); + char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len); efi_status_t efi_get_memory_map(struct efi_boot_memmap *map); diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c index 630caa6b1f4c..4e81c6077188 100644 --- a/drivers/firmware/efi/libstub/file.c +++ b/drivers/firmware/efi/libstub/file.c @@ -136,7 +136,7 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t *image, unsigned long *load_size) { const efi_char16_t *cmdline = image->load_options; - int cmdline_len = image->load_options_size / 2; + int cmdline_len = image->load_options_size; unsigned long efi_chunk_size = ULONG_MAX; efi_file_protocol_t *volume = NULL; efi_file_protocol_t *file; @@ -148,6 +148,9 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t *image, if (!load_addr || !load_size) return EFI_INVALID_PARAMETER; + efi_apply_loadoptions_quirk((const void **)&cmdline, &cmdline_len); + cmdline_len /= sizeof(*cmdline); + if (IS_ENABLED(CONFIG_X86) && !efi_nochunk) efi_chunk_size = EFI_READ_CHUNK_SIZE; -- 2.26.2
