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

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>
CC: <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 45e57cc38200448da67b1ce2c896efff555f0e73..bb84d7c7a1929f0b1da1026fefd70fe129339114 100644 (file)
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -421,7 +421,7 @@ 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 >= MAX_DOMAINNAME_SIZE)
                                break;
                        if (!ses->domainName) {
                                ses->domainName =

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 1fdc370410576e1a3f5a36a133245468160ae4b4..1ca7136ddf0ae8bbcd27360592d305e2d88e6d71 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 MAX_DOMAINNAME_SIZE 256        /* maximum fully qualified domain name (FQDN) */
 #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 fa68813396b5acb7e7a2e5a65e1202d740688cbb..3f9dcf7f2662433af215992ad49e15aa9798ce34 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1675,7 +1675,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                        if (string == NULL)
                                goto out_nomem;
 
-                       if (strnlen(string, 256) == 256) {
+                       if (strnlen(string, MAX_DOMAINNAME_SIZE)
+                                       == MAX_DOMAINNAME_SIZE) {
                                printk(KERN_WARNING "CIFS: domain name too"
                                                    " long\n");
                                goto cifs_parse_mount_err;
@@ -2276,8 +2277,8 @@ 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:") + MAX_DOMAINNAME_SIZE + 1 */
+#define CIFSCREDS_DESC_SIZE (7 + MAX_DOMAINNAME_SIZE + 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 79358e341fd2ea63cff42e6d608c58f65b5f9804..57b153782eb4917041d643ca5833b199cbd54353 100644 (file)
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -197,7 +197,7 @@ 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);
+                                           MAX_DOMAINNAME_SIZE, nls_cp);
        bcc_ptr += 2 * bytes_ret;
        bcc_ptr += 2;  /* account for null terminator */
 
@@ -255,8 +255,8 @@ 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, MAX_DOMAINNAME_SIZE);
+               bcc_ptr += strnlen(ses->domainName, MAX_DOMAINNAME_SIZE);
        } /* else we will send a null domain name
             so the server will default to its own domain */
        *bcc_ptr = 0;