Issue 711: Be more careful about verifying filename lengths when writing ISO9660...

* Don't cast size_t to int, since this can lead to overflow
  on machines where sizeof(int) < sizeof(size_t)
* Check a + b > limit by writing it as
    a > limit || b > limit || a + b > limit
  to avoid problems when a + b wraps around.

diff --git a/libarchive/archive_write_set_format_iso9660.c b/libarchive/archive_write_set_format_iso9660.c
index 4d832fb6e6e0eed57f00f3784eb7410fe1710dc5..cb3e54e8d21b10ece9a241f638c63ccbcec358b6 100644 (file)
--- a/libarchive/archive_write_set_format_iso9660.c
+++ b/libarchive/archive_write_set_format_iso9660.c
@@ -6225,7 +6225,7 @@ isoent_gen_joliet_identifier(struct archive_write *a, struct isoent *isoent,
        unsigned char *p;
        size_t l;
        int r;
-       int ffmax, parent_len;
+       size_t ffmax, parent_len;
        static const struct archive_rb_tree_ops rb_ops = {
                isoent_cmp_node_joliet, isoent_cmp_key_joliet
        };
@@ -6239,7 +6239,7 @@ isoent_gen_joliet_identifier(struct archive_write *a, struct isoent *isoent,
        else
                ffmax = 128;
 
-       r = idr_start(a, idr, isoent->children.cnt, ffmax, 6, 2, &rb_ops);
+       r = idr_start(a, idr, isoent->children.cnt, (int)ffmax, 6, 2, &rb_ops);
        if (r < 0)
                return (r);
 
@@ -6252,7 +6252,7 @@ isoent_gen_joliet_identifier(struct archive_write *a, struct isoent *isoent,
                int ext_off, noff, weight;
                size_t lt;
 
-               if ((int)(l = np->file->basename_utf16.length) > ffmax)
+               if ((l = np->file->basename_utf16.length) > ffmax)
                        l = ffmax;
 
                p = malloc((l+1)*2);
@@ -6285,7 +6285,7 @@ isoent_gen_joliet_identifier(struct archive_write *a, struct isoent *isoent,
                /*
                 * Get a length of MBS of a full-pathname.
                 */
-               if ((int)np->file->basename_utf16.length > ffmax) {
+               if (np->file->basename_utf16.length > ffmax) {
                        if (archive_strncpy_l(&iso9660->mbs,
                            (const char *)np->identifier, l,
                                iso9660->sconv_from_utf16be) != 0 &&
@@ -6302,7 +6302,9 @@ isoent_gen_joliet_identifier(struct archive_write *a, struct isoent *isoent,
 
                /* If a length of full-pathname is longer than 240 bytes,
                 * it violates Joliet extensions regulation. */
-               if (parent_len + np->mb_len > 240) {
+               if (parent_len > 240
+                   || np->mb_len > 240
+                   || parent_len + np->mb_len > 240) {
                        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
                            "The regulation of Joliet extensions;"
                            " A length of a full-pathname of `%s' is "
@@ -6314,11 +6316,11 @@ isoent_gen_joliet_identifier(struct archive_write *a, struct isoent *isoent,
 
                /* Make an offset of the number which is used to be set
                 * hexadecimal number to avoid duplicate identifier. */
-               if ((int)l == ffmax)
+               if (l == ffmax)
                        noff = ext_off - 6;
-               else if ((int)l == ffmax-2)
+               else if (l == ffmax-2)
                        noff = ext_off - 4;
-               else if ((int)l == ffmax-4)
+               else if (l == ffmax-4)
                        noff = ext_off - 2;
                else
                        noff = ext_off;