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authorAndrew Gabbasov <andrew_gabbasov@mentor.com>2015-12-24 10:25:33 -0600
committerJan Kara <jack@suse.cz>2016-01-04 15:57:49 +0100
commitbb00c898ad1ce40c4bb422a8207ae562e9aea7ae (patch)
treedca567eb137f212cab63c725599aafdd62e84129 /fs/udf
parentad402b265ecf6fa22d04043b41444cdfcdf4f52d (diff)
udf: Check output buffer length when converting name to CS0
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 <andrew_gabbasov@mentor.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf')
-rw-r--r--fs/udf/unicode.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index 95a224b26048..e788a05aab83 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -177,17 +177,22 @@ int udf_CS0toUTF8(struct ustr *utf_o, const struct ustr *ocu_i)
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 */
@@ -229,6 +234,7 @@ try_again:
if (max_val == 0xffU) {
max_val = 0xffffU;
ocu[0] = (uint8_t)0x10U;
+ u_ch = 2;
goto try_again;
}
goto error_out;
@@ -299,15 +305,19 @@ static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
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;
@@ -320,6 +330,7 @@ try_again:
if (uni_char > max_val) {
max_val = 0xffffU;
ocu[0] = (uint8_t)0x10U;
+ u_ch = 2;
goto try_again;
}