There is no practical reason to set a maxmum length of text either for file path or whole device path in device path-to-text conversion.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- lib/efi_loader/efi_device_path_to_text.c | 90 +++++++++++++++++++++--- 1 file changed, 80 insertions(+), 10 deletions(-)
diff --git a/lib/efi_loader/efi_device_path_to_text.c b/lib/efi_loader/efi_device_path_to_text.c index b158641e3043..75aabe66bf77 100644 --- a/lib/efi_loader/efi_device_path_to_text.c +++ b/lib/efi_loader/efi_device_path_to_text.c @@ -7,12 +7,12 @@
#include <common.h> #include <efi_loader.h> +#include <malloc.h>
#define MAC_OUTPUT_LEN 22 #define UNKNOWN_OUTPUT_LEN 23
#define MAX_NODE_LEN 512 -#define MAX_PATH_LEN 1024
const efi_guid_t efi_guid_device_path_to_text_protocol = EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID; @@ -228,8 +228,7 @@ static char *dp_media(char *s, struct efi_device_path *dp) struct efi_device_path_file_path *fp = (struct efi_device_path_file_path *)dp; int slen = (dp->length - sizeof(*dp)) / 2; - if (slen > MAX_NODE_LEN - 2) - slen = MAX_NODE_LEN - 2; + s += sprintf(s, "%-.*ls", slen, fp->str); break; } @@ -240,6 +239,31 @@ static char *dp_media(char *s, struct efi_device_path *dp) return s; }
+/* + * Return a maximum size of buffer to be allocated for conversion + * + * @dp device path or node + * @return maximum size of buffer + */ +static size_t efi_dp_text_max(struct efi_device_path *dp) +{ + /* + * We don't have be very accurate here. + * Currently, there are only two cases where a maximum size + * of buffer may go over MAX_NODE_LEN. + */ + if (dp->type == DEVICE_PATH_TYPE_HARDWARE_DEVICE && + dp->sub_type == DEVICE_PATH_SUB_TYPE_VENDOR) + /* VenHw(<guid>, xxxxxxxx...) */ + return 8 + 36 + (dp->length - sizeof(*dp)) * 2 + 1; + + if (dp->type == DEVICE_PATH_TYPE_MEDIA_DEVICE && + dp->sub_type == DEVICE_PATH_SUB_TYPE_FILE_PATH) + return dp->length - sizeof(*dp) + 2 /* u16 NULL */; + + return MAX_NODE_LEN; +} + /* * Converts a single node to a char string. * @@ -293,16 +317,27 @@ static uint16_t EFIAPI *efi_convert_device_node_to_text( bool display_only, bool allow_shortcuts) { - char str[MAX_NODE_LEN]; + char *str; + size_t str_size; uint16_t *text = NULL;
EFI_ENTRY("%p, %d, %d", device_node, display_only, allow_shortcuts);
if (!device_node) goto out; + + str_size = efi_dp_text_max(device_node); + if (!str_size) + goto out; + + str = malloc(str_size); + if (!str) + goto out; + efi_convert_single_device_node_to_text(str, device_node);
text = efi_str_to_u16(str); + free(str);
out: EFI_EXIT(EFI_SUCCESS); @@ -327,24 +362,59 @@ static uint16_t EFIAPI *efi_convert_device_path_to_text( bool allow_shortcuts) { uint16_t *text = NULL; - char buffer[MAX_PATH_LEN]; - char *str = buffer; + char *buffer = NULL, *str; + size_t buf_size, buf_left; + efi_status_t ret = EFI_SUCCESS;
EFI_ENTRY("%p, %d, %d", device_path, display_only, allow_shortcuts);
- if (!device_path) + if (!device_path) { + ret = EFI_INVALID_PARAMETER; goto out; - while (device_path && - str + MAX_NODE_LEN < buffer + MAX_PATH_LEN) { + } + + buf_size = 1024; + buf_left = buf_size; + buffer = malloc(buf_size); + if (!buffer) { + ret = EFI_OUT_OF_RESOURCES; + goto out; + } + + str = buffer; + while (device_path) { + char *buf_new; + size_t buf_new_size, dp_text_len; + *str++ = '/'; + buf_left--; + dp_text_len = efi_dp_text_max(device_path); + if (buf_left < dp_text_len) { + buf_new_size = buf_size + dp_text_len; + buf_new = malloc(buf_new_size); + if (!buf_new) { + ret = EFI_OUT_OF_RESOURCES; + goto out; + } + + memcpy(buf_new, buffer, str - buffer); + buf_left = buf_new_size - (str - buffer); + str = buf_new + (str - buffer); + free(buffer); + buffer = buf_new; + } + str = efi_convert_single_device_node_to_text(str, device_path); + device_path = efi_dp_next(device_path); }
text = efi_str_to_u16(buffer);
out: - EFI_EXIT(EFI_SUCCESS); + free(buffer); + EFI_EXIT(ret); + return text; }