BUG memory leakage at ./security/selinux/hooks.c

[iceberg <strakh@ispras.ru>]

        KERNEL_VERSION: 2.6.30.4
        SUBJECT:  in function inode_doinit_with_dentry memory is not released 
on error  path (if rc<0).
        DESCRIBE:
        In ./security/selinux/hooks.c in function inode_doinit_with_dentry:
1. If in the line 1278 we successfully allocate memory and assign it to 
context variablehen
2. if in the line 1284 getxattr returns -ERANGE and
3. if in the line 1288 getxattr returns rc<0
then we go to out_unlock without releasing memory pointed to by context 
variable.

1278                 context = kmalloc(len, GFP_NOFS);
1279                 if (!context) {
1280                         rc = -ENOMEM;
1281                         dput(dentry);
1282                         goto out_unlock;
1283                 }
1284                 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1285                                            context, len);
1286                 if (rc == -ERANGE) {
1287                         /* Need a larger buffer.  Query for the
right size. */
1288                         rc = inode->i_op->getxattr(dentry,
XATTR_NAME_SELINUX,
1289                                                    NULL, 0);
1290                         if (rc < 0) {
1291                                 dput(dentry);
1292                                 goto out_unlock;
1293                         }
1294                         kfree(context);
1295                         len = rc;
1296                         context = kmalloc(len, GFP_NOFS);