This is a note to let you know that I've just added the patch titled udf: Check output buffer length when converting name to CS0 to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: udf-check-output-buffer-length-when-converting-name-to-cs0.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bb00c898ad1ce40c4bb422a8207ae562e9aea7ae Mon Sep 17 00:00:00 2001 From: Andrew Gabbasov <andrew_gabbasov@xxxxxxxxxx> Date: Thu, 24 Dec 2015 10:25:33 -0600 Subject: udf: Check output buffer length when converting name to CS0 From: Andrew Gabbasov <andrew_gabbasov@xxxxxxxxxx> commit bb00c898ad1ce40c4bb422a8207ae562e9aea7ae upstream. 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] Signed-off-by: Andrew Gabbasov <andrew_gabbasov@xxxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/udf/unicode.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/fs/udf/unicode.c +++ b/fs/udf/unicode.c @@ -181,17 +181,22 @@ int udf_CS0toUTF8(struct ustr *utf_o, co static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length) { unsigned c, i, max_val, utf_char; - int utf_cnt, u_len; + int utf_cnt, u_len, u_ch; memset(ocu, 0, sizeof(dstring) * length); ocu[0] = 8; max_val = 0xffU; + u_ch = 1; try_again: u_len = 0U; utf_char = 0U; utf_cnt = 0U; for (i = 0U; i < utf->u_len; i++) { + /* Name didn't fit? */ + if (u_len + 1 + u_ch >= length) + return 0; + c = (uint8_t)utf->u_name[i]; /* Complete a multi-byte UTF-8 character */ @@ -233,6 +238,7 @@ try_again: if (max_val == 0xffU) { max_val = 0xffffU; ocu[0] = (uint8_t)0x10U; + u_ch = 2; goto try_again; } goto error_out; @@ -303,15 +309,19 @@ static int udf_NLStoCS0(struct nls_table int len; unsigned i, max_val; uint16_t uni_char; - int u_len; + int u_len, u_ch; memset(ocu, 0, sizeof(dstring) * length); ocu[0] = 8; max_val = 0xffU; + u_ch = 1; try_again: u_len = 0U; for (i = 0U; i < uni->u_len; i++) { + /* Name didn't fit? */ + if (u_len + 1 + u_ch >= length) + return 0; len = nls->char2uni(&uni->u_name[i], uni->u_len - i, &uni_char); if (!len) continue; @@ -324,6 +334,7 @@ try_again: if (uni_char > max_val) { max_val = 0xffffU; ocu[0] = (uint8_t)0x10U; + u_ch = 2; goto try_again; } Patches currently in stable-queue which might be from andrew_gabbasov@xxxxxxxxxx are queue-3.14/udf-check-output-buffer-length-when-converting-name-to-cs0.patch queue-3.14/udf-prevent-buffer-overrun-with-multi-byte-characters.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html