user/sven/linux.git/fs/udf/unicode.c, branch v4.8.5

udf: Fix conversion of 'dstring' fields to UTF8

2016-04-25T13:18:50Z

Commit 9293fcfbc1812a22ad5ce1b542eb90c1bbe01be1 ("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 484a10f49387e4386bf2708532e75bf78ffea2cb ("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 character. 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: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Merge linux specific translation into CS0 conversion function

2016-02-09T12:05:23Z

Current implementation of udf_translate_to_linux function does not support multi-bytes characters at all: it counts bytes while calculating extension length, when inserting CRC inside the name it doesn't take into account inter-character boundaries and can break into the middle of the character. The most efficient way to properly support multi-bytes characters is merging of translation operations directly into conversion function. This can help to avoid extra passes along the string or parsing the multi-bytes character back into unicode to find out it's length. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Remove struct ustr as non-needed intermediate storage

2016-02-09T12:05:23Z

Although 'struct ustr' tries to structurize the data by combining the string and its length, it doesn't actually make much benefit, since it saves only one parameter, but introduces an extra copying of the whole buffer, serving as an intermediate storage. It looks quite inefficient and not actually needed. This commit gets rid of the struct ustr by changing the parameters of some functions appropriately. Also, it removes using 'dstring' type, since it doesn't make much sense too. Just using the occasion, add a 'const' qualifier to udf_get_filename to make consistent parameters sets. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Adjust UDF_NAME_LEN to better reflect actual restrictions

2016-02-09T12:05:23Z

Actual name length restriction is 254 bytes, this is used in 'ustr' structure, and this is what fits into UDF File Ident structures. And in most cases the constant is used as UDF_NAME_LEN-2. So, it's better to just modify the constant to make it closer to reality. Also, in some cases it's useful to have a separate constant for the maximum length of file name field in CS0 encoding in UDF File Ident structures. Also, remove the unused UDF_PATH_LEN constant. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Join functions for UTF8 and NLS conversions

2016-02-09T12:05:23Z

There is no much sense to have separate functions for UTF8 and NLS conversions, since UTF8 encoding is actually the special case of NLS. However, although UTF8 is also supported by general NLS framework, it would be good to have separate UTF8 character conversion functions (char2uni and uni2char) locally in UDF code, so that they could be used even if NLS support is not enabled in the kernel configuration. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Parameterize output length in udf_put_filename

2016-02-09T12:05:23Z

Make the desired output length a parameter rather than have it hard-coded to UDF_NAME_LEN. Although all call sites still have this length the same, this parameterization will make the function more universal and also consistent with udf_get_filename. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Check output buffer length when converting name to CS0

2016-01-04T14:57:49Z

If a name contains at least some characters with Unicode values exceeding single byte, the CS0 output should have 2 bytes per character. And if other input characters have single byte Unicode values, then the single input byte is converted to 2 output bytes, and the length of output becomes larger than the length of input. And if the input name is long enough, the output length may exceed the allocated buffer length. All this means that conversion from UTF8 or NLS to CS0 requires checking of output length in order to stop when it exceeds the given output buffer size. [JK: Make code return -ENAMETOOLONG instead of silently truncating the name] CC: stable@vger.kernel.org Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Prevent buffer overrun with multi-byte characters

2016-01-04T13:30:43Z

udf_CS0toUTF8 function stops the conversion when the output buffer length reaches UDF_NAME_LEN-2, which is correct maximum name length, but, when checking, it leaves the space for a single byte only, while multi-bytes output characters can take more space, causing buffer overflow. Similar error exists in udf_CS0toNLS function, that restricts the output length to UDF_NAME_LEN, while actual maximum allowed length is UDF_NAME_LEN-2. In these cases the output can override not only the current buffer length field, causing corruption of the name buffer itself, but also following allocation structures, causing kernel crash. Adjust the output length checks in both functions to prevent buffer overruns in case of multi-bytes UTF8 or NLS characters. CC: stable@vger.kernel.org Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Make udf_get_filename() return error instead of 0 length file name

2015-05-18T09:23:06Z

Zero length file name isn't really valid. So check the length of the final file name generated by udf_translate_to_linux() and return -EINVAL instead of zero length file name. Update caller of udf_get_filename() to not check for 0 return value. Signed-off-by: Fabian Frederick Signed-off-by: Jan Kara

udf: bug on exotic flag in udf_get_filename()

2015-05-18T09:23:06Z

UDF volume is only mounted with UDF_FLAG_UTF8 or UDF_FLAG_NLS_MAP (see fill udf_fill_super(). BUG() if we have something different in udf_get_filename() Suggested-by: Jan Kara Signed-off-by: Fabian Frederick Signed-off-by: Jan Kara