[PATCH v2] cifs: extend the buffer length enought for sprintf() using
Steve French
smfrench at gmail.com
Tue Jul 30 22:59:59 MDT 2013
I updated the version of the patch slightly which is in cifs-2.6.git
so we don't have to rename the MAX_DOMAINNAME_SIZE field multiple
times. Let me know if you see problems. It could make Scott's
followup patch a little easier to understand without the renamed
#define.
commit 057d6332b24a4497c55a761c83c823eed9e3f23b
Author: Chen Gang <gang.chen at asianux.com>
Date: Fri Jul 19 09:01:36 2013 +0800
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 at asianux.com>
Reviewed-by: Jeff Layton <jlayton at redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar at gmail.com>
Reviewed-by: Scott Lovenberg <scott.lovenberg at gmail.com>
CC: <stable at vger.kernel.org>
Signed-off-by: Steve French <smfrench at gmail.com>
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 45e57cc..194f9cc 100644
--- 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 >= CIFS_MAX_DOMAINNAME_LEN)
break;
if (!ses->domainName) {
ses->domainName =
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 1fdc370..0e68893 100644
--- 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 fa68813..d67c550 100644
--- 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, CIFS_MAX_DOMAINNAME_LEN)
+ == CIFS_MAX_DOMAINNAME_LEN) {
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:") + 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 79358e3..08dd37b 100644
--- 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);
+ CIFS_MAX_DOMAINNAME_LEN, 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, 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;
On Sun, Jul 21, 2013 at 8:21 PM, Chen Gang <gang.chen at asianux.com> wrote:
> On 07/19/2013 11:46 PM, Steve French wrote:
>> merged into cifs-2.6.git
>>
>
> Thanks.
>
>> On Fri, Jul 19, 2013 at 5:45 AM, Jeff Layton <jlayton at redhat.com> wrote:
>>> > On Fri, 19 Jul 2013 09:01:36 +0800
>>> > Chen Gang <gang.chen at asianux.com> wrote:
>>> >
>>>> >> 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 at asianux.com>
>>>> >> ---
>>>> >> 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(-)
>>>> >>
>>>> >> diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
>>>> >> index 45e57cc..bb84d7c 100644
>>>> >> --- 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 33f17ed..64bb4c5 100644
>>>> >> --- 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 fa68813..3f9dcf7 100644
>>>> >> --- 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 79358e3..57b1537 100644
>>>> >> --- 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;
>>> >
>>> > Looks good...
>>> >
>>> > Reviewed-by: Jeff Layton <jlayton at redhat.com>
>>
>>
>> -- Thanks, Steve
>>
>
>
> --
> Chen Gang
--
Thanks,
Steve
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