Shrink stack space usage in cifs_construct_tcon

We were reserving MAX_USERNAME (now 256) on stack for
something which only needs to fit about 24 bytes ie
string krb50x +  printf version of uid

Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 6e211b6..108a1e9 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -274,7 +274,8 @@ struct cifsSesInfo {
        int capabilities;
        char serverName[SERVER_NAME_LEN_WITH_NULL * 2]; /* BB make bigger for
                                TCP names - will ipv6 and sctp addresses fit? */
-       char *user_name;
+       char *user_name;        /* must not be null except during init of sess
+                                  and after mount option parsing we fill it */
        char *domainName;
        char *password;
        struct session_key auth_key;

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 68b7dbf..8d72acb 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3258,7 +3258,9 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid)
        struct cifsSesInfo *ses;
        struct cifsTconInfo *tcon = NULL;
        struct smb_vol *vol_info;
-       char username[MAX_USERNAME_SIZE + 1];
+       char username[28]; /* big enough for "krb50x" + hex of ULONG_MAX 6+16 */
+                          /* We used to have this as MAX_USERNAME which is   */
+                          /* way too big now (256 instead of 32) */
 
        vol_info = kzalloc(sizeof(*vol_info), GFP_KERNEL);
        if (vol_info == NULL) {