• Andrew Gabbasov's avatar
    udf: Fix conversion of 'dstring' fields to UTF8 · c26f6c61
    Andrew Gabbasov authored
    Commit 9293fcfb
    ("udf: Remove struct ustr as non-needed intermediate storage"),
    while getting rid of 'struct ustr', does not take any special care
    of 'dstring' fields and effectively use fixed field length instead
    of actual string length, encoded in the last byte of the field.
    Also, commit 484a10f4
    ("udf: Merge linux specific translation into CS0 conversion function")
    introduced checking of the length of the string being converted,
    requiring proper alignment to number of bytes constituing each
    The UDF volume identifier is represented as a 32-bytes 'dstring',
    and needs to be converted from CS0 to UTF8, while mounting UDF
    filesystem. The changes in mentioned commits can in some cases
    lead to incorrect handling of volume identifier:
    - if the actual string in 'dstring' is of maximal length and
    does not have zero bytes separating it from dstring encoded
    length in last byte, that last byte may be included in conversion,
    thus making incorrect resulting string;
    - if the identifier is encoded with 2-bytes characters (compression
    code is 16), the length of 31 bytes (32 bytes of field length minus
    1 byte of compression code), taken as the string length, is reported
    as an incorrect (unaligned) length, and the conversion fails, which
    in its turn leads to volume mounting failure.
    This patch introduces handling of 'dstring' encoded length field
    in udf_CS0toUTF8 function, that is used in all and only cases
    when 'dstring' fields are converted. Currently these cases are
    processing of Volume Identifier and Volume Set Identifier fields.
    The function is also renamed to udf_dstrCS0toUTF8 to distinctly
    indicate that it handles 'dstring' input.
    Signed-off-by: default avatarAndrew Gabbasov <andrew_gabbasov@mentor.com>
    Signed-off-by: default avatarJan Kara <jack@suse.cz>
unicode.c 8.76 KB