cifs: extend the buffer length enought for sprintf() using

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>

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index f59d0d5..5c807b2 100644 (file)
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -389,7 +389,7 @@ find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
                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 =

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 4f07f6f..ea3a0b3 100644 (file)
--- 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 */
 

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e3bc39b..d6a5c5a 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1662,7 +1662,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                        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

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index f230571..8edc9eb 100644 (file)
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -198,7 +198,7 @@ static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
                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 **pbcc_area, struct cifs_ses *ses,
 
        /* 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;