From 59285c28d18b77437e6dc7c2abb9aaee10ec3a75 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 4 Feb 2009 19:46:11 +0100 Subject: 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 --- fs/udf/unicode.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'fs/udf') diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c index a3bbdbde9f4b..cefa8c8913e6 100644 --- a/fs/udf/unicode.c +++ b/fs/udf/unicode.c @@ -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; -- cgit v1.2.3-58-ga151