4 files changed, 108 insertions, 0 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 7aab6ab7c57f..d4f3b7a94ea6 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -250,6 +250,25 @@ struct swap_info_struct;
  *      @inode contains the inode structure.
  *      Deallocate the inode security structure and set @inode->i_security to
  *      NULL. 
+ * @inode_init_security:
+ *      Obtain the security attribute name suffix and value to set on a newly
+ *      created inode and set up the incore security field for the new inode.
+ *      This hook is called by the fs code as part of the inode creation
+ *      transaction and provides for atomic labeling of the inode, unlike
+ *      the post_create/mkdir/... hooks called by the VFS.  The hook function
+ *      is expected to allocate the name and value via kmalloc, with the caller
+ *      being responsible for calling kfree after using them.
+ *      If the security module does not use security attributes or does
+ *      not wish to put a security attribute on this particular inode,
+ *      then it should return -EOPNOTSUPP to skip this processing.
+ *      @inode contains the inode structure of the newly created inode.
+ *      @dir contains the inode structure of the parent directory.
+ *      @name will be set to the allocated name suffix (e.g. selinux).
+ *      @value will be set to the allocated attribute value.
+ *      @len will be set to the length of the value.
+ *      Returns 0 if @name and @value have been successfully set,
+ *              -EOPNOTSUPP if no security attribute is needed, or
+ *              -ENOMEM on memory allocation failure.
  * @inode_create:
  *      Check permission to create a regular file.
  *      @dir contains inode structure of the parent of the new file.
@@ -1080,6 +1099,8 @@ struct security_operations {
 
         int (*inode_alloc_security) (struct inode *inode);      
         void (*inode_free_security) (struct inode *inode);
+        int (*inode_init_security) (struct inode *inode, struct inode *dir,
+                                    char **name, void **value, size_t *len);
         int (*inode_create) (struct inode *dir,
                              struct dentry *dentry, int mode);
         void (*inode_post_create) (struct inode *dir,
@@ -1442,6 +1463,17 @@ static inline void security_inode_free (struct inode *inode)
                 return;
         security_ops->inode_free_security (inode);
 }
+
+static inline int security_inode_init_security (struct inode *inode,
+                                                struct inode *dir,
+                                                char **name,
+                                                void **value,
+                                                size_t *len)
+{
+        if (unlikely (IS_PRIVATE (inode)))
+                return -EOPNOTSUPP;
+        return security_ops->inode_init_security (inode, dir, name, value, len);
+}
         
 static inline int security_inode_create (struct inode *dir,
                                          struct dentry *dentry,
@@ -2171,6 +2203,15 @@ static inline int security_inode_alloc (struct inode *inode)
 
 static inline void security_inode_free (struct inode *inode)
 { }
+
+static inline int security_inode_init_security (struct inode *inode,
+                                                struct inode *dir,
+                                                char **name,
+                                                void **value,
+                                                size_t *len)
+{
+        return -EOPNOTSUPP;
+}
         
 static inline int security_inode_create (struct inode *dir,
                                          struct dentry *dentry,
diff --git a/security/dummy.c b/security/dummy.c
index 6ff887586479..e8a00fa80469 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -258,6 +258,12 @@ static void dummy_inode_free_security (struct inode *inode)
         return;
 }
 
+static int dummy_inode_init_security (struct inode *inode, struct inode *dir,
+                                      char **name, void **value, size_t *len)
+{
+        return -EOPNOTSUPP;
+}
+
 static int dummy_inode_create (struct inode *inode, struct dentry *dentry,
                                int mask)
 {
@@ -886,6 +892,7 @@ void security_fixup_ops (struct security_operations *ops)
         set_to_dummy_if_null(ops, sb_post_pivotroot);
         set_to_dummy_if_null(ops, inode_alloc_security);
         set_to_dummy_if_null(ops, inode_free_security);
+        set_to_dummy_if_null(ops, inode_init_security);
         set_to_dummy_if_null(ops, inode_create);
         set_to_dummy_if_null(ops, inode_post_create);
         set_to_dummy_if_null(ops, inode_link);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8641f8894b4c..63701fe0e1ad 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1274,6 +1274,7 @@ static int post_create(struct inode *dir,
         struct inode *inode;
         struct inode_security_struct *dsec;
         struct superblock_security_struct *sbsec;
+        struct inode_security_struct *isec;
         u32 newsid;
         char *context;
         unsigned int len;
@@ -1293,6 +1294,11 @@ static int post_create(struct inode *dir,
                 return 0;
         }
 
+        isec = inode->i_security;
+
+        if (isec->security_attr_init)
+                return 0;
+
         if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
                 newsid = tsec->create_sid;
         } else {
@@ -2018,6 +2024,58 @@ static void selinux_inode_free_security(struct inode *inode)
         inode_free_security(inode);
 }
 
+static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
+                                       char **name, void **value,
+                                       size_t *len)
+{
+        struct task_security_struct *tsec;
+        struct inode_security_struct *dsec;
+        struct superblock_security_struct *sbsec;
+        struct inode_security_struct *isec;
+        u32 newsid;
+        int rc;
+        char *namep, *context;
+
+        tsec = current->security;
+        dsec = dir->i_security;
+        sbsec = dir->i_sb->s_security;
+        isec = inode->i_security;
+
+        if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
+                newsid = tsec->create_sid;
+        } else {
+                rc = security_transition_sid(tsec->sid, dsec->sid,
+                                             inode_mode_to_security_class(inode->i_mode),
+                                             &newsid);
+                if (rc) {
+                        printk(KERN_WARNING "%s:  "
+                               "security_transition_sid failed, rc=%d (dev=%s "
+                               "ino=%ld)\n",
+                               __FUNCTION__,
+                               -rc, inode->i_sb->s_id, inode->i_ino);
+                        return rc;
+                }
+        }
+
+        inode_security_set_sid(inode, newsid);
+
+        namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
+        if (!namep)
+                return -ENOMEM;
+        *name = namep;
+
+        rc = security_sid_to_context(newsid, &context, len);
+        if (rc) {
+                kfree(namep);
+                return rc;
+        }
+        *value = context;
+
+        isec->security_attr_init = 1;
+
+        return 0;
+}
+
 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
 {
         return may_create(dir, dentry, SECCLASS_FILE);
@@ -4298,6 +4356,7 @@ static struct security_operations selinux_ops = {
 
         .inode_alloc_security =         selinux_inode_alloc_security,
         .inode_free_security =          selinux_inode_free_security,
+        .inode_init_security =          selinux_inode_init_security,
         .inode_create =                 selinux_inode_create,
         .inode_post_create =            selinux_inode_post_create,
         .inode_link =                   selinux_inode_link,
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 887937c8134a..c515bc0b58a1 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -46,6 +46,7 @@ struct inode_security_struct {
         unsigned char initialized;     /* initialization flag */
         struct semaphore sem;
         unsigned char inherit;         /* inherit SID from parent entry */
+        unsigned char security_attr_init; /* security attributes init flag */
 };
 
 struct file_security_struct {