libblkid: udf: check that dstrings are encoded in OSTA Compressed Unicode

dstring structures are in UL_ENCODE_LATIN1/UL_ENCODE_UTF16BE encodings only
when corresponding desc_charset structures are set to the OSTA Compressed
Unicode. So add missing checks.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>

diff --git a/libblkid/src/superblocks/udf.c b/libblkid/src/superblocks/udf.c
index 1d7820ff19139615c127a410f994cbd33326b062..e030b81b3e37d3ad215456443cf31a935e576290 100644 (file)
--- a/libblkid/src/superblocks/udf.c
+++ b/libblkid/src/superblocks/udf.c
@@ -19,8 +19,15 @@
 
 #include "superblocks.h"
 
+#define is_charset_udf(charspec) ((charspec).type == 0 && strncmp((charspec).info, "OSTA Compressed Unicode", sizeof((charspec).info)) == 0)
+
 #define udf_cid_to_enc(cid) ((cid) == 8 ? UL_ENCODE_LATIN1 : (cid) == 16 ? UL_ENCODE_UTF16BE : -1)
 
+struct charspec {
+       uint8_t type;
+       char    info[63];
+} __attribute__((packed));
+
 struct dstring128 {
        uint8_t cid;
        uint8_t c[126];
@@ -62,11 +69,12 @@ struct volume_descriptor {
                        uint32_t        charset_list;
                        uint32_t        max_charset_list;
                        struct dstring128 volset_id;
+                       struct charspec desc_charset;
                } __attribute__((packed)) primary;
 
                struct logical_descriptor {
                        uint32_t        seq_num;
-                       uint8_t         desc_charset[64];
+                       struct charspec desc_charset;
                        struct dstring128 logvol_id;
                        uint32_t        logical_blocksize;
                        uint8_t         domain_id_flags;
@@ -322,7 +330,7 @@ real_blksz:
                if (type == TAG_ID_TD)
                        break;
                if (type == TAG_ID_PVD) {
-                       if (!have_volid) {
+                       if (!have_volid && is_charset_udf(vd->type.primary.desc_charset)) {
                                int enc = udf_cid_to_enc(vd->type.primary.ident.cid);
                                uint8_t clen = vd->type.primary.ident.clen;
                                if (clen > 0)
@@ -333,7 +341,7 @@ real_blksz:
                                        have_volid = !blkid_probe_set_utf8_id_label(pr, "VOLUME_ID",
                                                        vd->type.primary.ident.c, clen, enc);
                        }
-                       if (!have_uuid) {
+                       if (!have_uuid && is_charset_udf(vd->type.primary.desc_charset)) {
                                /* VolumeSetIdentifier in UDF 2.01 specification:
                                 * =================================================================================
                                 * 2.2.2.5 dstring VolumeSetIdentifier
@@ -367,7 +375,7 @@ real_blksz:
                                if (gen_uuid_from_volset_id(uuid, &vd->type.primary.volset_id) == 0)
                                        have_uuid = !blkid_probe_strncpy_uuid(pr, uuid, sizeof(uuid));
                        }
-                       if (!have_volsetid) {
+                       if (!have_volsetid && is_charset_udf(vd->type.primary.desc_charset)) {
                                int enc = udf_cid_to_enc(vd->type.primary.volset_id.cid);
                                uint8_t clen = vd->type.primary.volset_id.clen;
                                if (clen > 0)
@@ -393,7 +401,7 @@ real_blksz:
                                if (strncmp(vd->type.logical.domain_id, "*OSTA UDF Compliant", sizeof(vd->type.logical.domain_id)) == 0)
                                        udf_rev = le16_to_cpu(vd->type.logical.udf_rev);
                        }
-                       if (!have_logvolid || !have_label) {
+                       if ((!have_logvolid || !have_label) && is_charset_udf(vd->type.logical.desc_charset)) {
                                /* LogicalVolumeIdentifier in UDF 2.01 specification:
                                 * ===============================================================
                                 * 2. Basic Restrictions & Requirements