cifs: fix IPv6 address length check

For IPv6 the userspace mount helper sends an address in the "ip="
option.  This check fails if the length is > 35 characters. I have no
idea where the magic 35 character limit came from, but it's clearly not
enough for IPv6. Fix it by making it use the INET6_ADDRSTRLEN #define.

While we're at it, use the same #define for the address length in SPNEGO
upcalls.

Reported-by: Charles R. Anderson <cra@wpi.edu>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

2 files changed, 5 insertions, 5 deletions

diff --git a/fs/cifs/cifs_spnego.c b/fs/cifs/cifs_spnego.c
index 67bf93a40d2e..4a4581cb2b5e 100644
--- a/fs/cifs/cifs_spnego.c
+++ b/fs/cifs/cifs_spnego.c
@@ -23,6 +23,7 @@
 #include <linux/string.h>
 #include <keys/user-type.h>
 #include <linux/key-type.h>
+#include <linux/inet.h>
 #include "cifsglob.h"
 #include "cifs_spnego.h"
 #include "cifs_debug.h"
@@ -73,9 +74,6 @@ struct key_type cifs_spnego_key_type = {
  * strlen(";sec=ntlmsspi") */
 #define MAX_MECH_STR_LEN        13
 
-/* max possible addr len eg FEDC:BA98:7654:3210:FEDC:BA98:7654:3210/128 */
-#define MAX_IPV6_ADDR_LEN       43
-
 /* strlen of "host=" */
 #define HOST_KEY_LEN            5
 
@@ -102,7 +100,7 @@ cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
            host=hostname sec=mechanism uid=0xFF user=username */
         desc_len = MAX_VER_STR_LEN +
                    HOST_KEY_LEN + strlen(hostname) +
-                   IP_KEY_LEN + MAX_IPV6_ADDR_LEN +
+                   IP_KEY_LEN + INET6_ADDRSTRLEN +
                    MAX_MECH_STR_LEN +
                    UID_KEY_LEN + (sizeof(uid_t) * 2) +
                    USER_KEY_LEN + strlen(sesInfo->userName) + 1;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8ae563f028bc..74b5a87e9195 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -35,6 +35,7 @@
 #include <linux/namei.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
+#include <linux/inet.h>
 #include <net/ipv6.h>
 #include "cifspdu.h"
 #include "cifsglob.h"
@@ -960,7 +961,8 @@ cifs_parse_mount_options(char *options, const char *devname,
                 } else if (strnicmp(data, "ip", 2) == 0) {
                         if (!value || !*value) {
                                 vol->UNCip = NULL;
-                        } else if (strnlen(value, 35) < 35) {
+                        } else if (strnlen(value, INET6_ADDRSTRLEN) <
+                                                        INET6_ADDRSTRLEN) {
                                 vol->UNCip = value;
                         } else {
                                 printk(KERN_WARNING "CIFS: ip address "