udf: Fix oops when invalid character in filename occurs

Functions udf_CS0toNLS() and udf_NLStoCS0() didn't count with the fact that
NLS can return negative length when invalid character is given to it for
conversion. Thus interesting things could happen (such as overwriting random
memory with the rest of filename). Add appropriate checks.

Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2009-02-04 19:46:11 +01:00
parent 557f5a1468
commit 59285c28d1

View File

@ -254,7 +254,7 @@ static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
{
const uint8_t *ocu;
uint8_t cmp_id, ocu_len;
int i;
int i, len;
ocu_len = ocu_i->u_len;
@ -279,8 +279,13 @@ static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
if (cmp_id == 16)
c = (c << 8) | ocu[i++];
utf_o->u_len += nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
UDF_NAME_LEN - utf_o->u_len);
len = nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
UDF_NAME_LEN - utf_o->u_len);
/* Valid character? */
if (len >= 0)
utf_o->u_len += len;
else
utf_o->u_name[utf_o->u_len++] = '?';
}
utf_o->u_cmpID = 8;
@ -290,7 +295,8 @@ static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
int length)
{
unsigned len, i, max_val;
int len;
unsigned i, max_val;
uint16_t uni_char;
int u_len;
@ -302,8 +308,13 @@ try_again:
u_len = 0U;
for (i = 0U; i < uni->u_len; i++) {
len = nls->char2uni(&uni->u_name[i], uni->u_len - i, &uni_char);
if (len <= 0)
if (!len)
continue;
/* Invalid character, deal with it */
if (len < 0) {
len = 1;
uni_char = '?';
}
if (uni_char > max_val) {
max_val = 0xffffU;