[ 48/60] cifs: extend the buffer length enought for sprintf() using

Greg Kroah-Hartman
2013-08-13T06:44:54Z

From: Chen Gang <gang.chen@asianux.com>

commit 057d6332b24a4497c55a761c83c823eed9e3f23b upstream.

For cifs_set_cifscreds() in "fs/cifs/connect.c", 'desc' buffer length
is 'CIFSCREDS_DESC_SIZE' (56 is less than 256), and 'ses->domainName'
length may be "255 + '\0'".

The related sprintf() may cause memory overflow, so need extend related
buffer enough to hold all things.

It is also necessary to be sure of 'ses->domainName' must be less than
256, and define the related macro instead of hard code number '256'.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Scott Lovenberg <scott.lovenberg@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/cifs/cifsencrypt.c | 2 +-
fs/cifs/cifsglob.h | 1 +
fs/cifs/connect.c | 7 ++++---
fs/cifs/sess.c | 6 +++---
4 files changed, 9 insertions(+), 7 deletions(-)

--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -389,7 +389,7 @@ find_domain_name(struct cifs_ses *ses, c
if (blobptr + attrsize > blobend)
break;
if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
- if (!attrsize)
+ if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
break;
if (!ses->domainName) {
ses->domainName =
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -44,6 +44,7 @@
#define MAX_TREE_SIZE (2 + MAX_SERVER_SIZE + 1 + MAX_SHARE_SIZE + 1)
#define MAX_SERVER_SIZE 15
#define MAX_SHARE_SIZE 80
+#define CIFS_MAX_DOMAINNAME_LEN 256 /* max domain name length */
#define MAX_USERNAME_SIZE 256 /* reasonable maximum for current servers */
#define MAX_PASSWORD_SIZE 512 /* max for windows seems to be 256 wide chars */

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1662,7 +1662,8 @@ cifs_parse_mount_options(const char *mou
if (string == NULL)
goto out_nomem;

- if (strnlen(string, 256) == 256) {
+ if (strnlen(string, CIFS_MAX_DOMAINNAME_LEN)
+ == CIFS_MAX_DOMAINNAME_LEN) {
printk(KERN_WARNING "CIFS: domain name too"
" long\n");
goto cifs_parse_mount_err;
@@ -2288,8 +2289,8 @@ cifs_put_smb_ses(struct cifs_ses *ses)

#ifdef CONFIG_KEYS

-/* strlen("cifs:a:") + INET6_ADDRSTRLEN + 1 */
-#define CIFSCREDS_DESC_SIZE (7 + INET6_ADDRSTRLEN + 1)
+/* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
+#define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)

/* Populate username and pw fields from keyring if possible */
static int
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -198,7 +198,7 @@ static void unicode_domain_string(char *
bytes_ret = 0;
} else
bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
- 256, nls_cp);
+ CIFS_MAX_DOMAINNAME_LEN, nls_cp);
bcc_ptr += 2 * bytes_ret;
bcc_ptr += 2; /* account for null terminator */

@@ -256,8 +256,8 @@ static void ascii_ssetup_strings(char **

/* copy domain */
if (ses->domainName != NULL) {
- strncpy(bcc_ptr, ses->domainName, 256);
- bcc_ptr += strnlen(ses->domainName, 256);
+ strncpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
+ bcc_ptr += strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
} /* else we will send a null domain name
so the server will default to its own domain */
*bcc_ptr = 0;