selinux: Implementation for inode_copy_up_xattr() hook

[linux-2.6-microblaze.git] / security / selinux / hooks.c

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 40597ed..a2d5108 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3313,6 +3313,21 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
        return 0;
 }
 
+static int selinux_inode_copy_up_xattr(const char *name)
+{
+       /* The copy_up hook above sets the initial context on an inode, but we
+        * don't then want to overwrite it by blindly copying all the lower
+        * xattrs up.  Instead, we have to filter out SELinux-related xattrs.
+        */
+       if (strcmp(name, XATTR_NAME_SELINUX) == 0)
+               return 1; /* Discard */
+       /*
+        * Any other attribute apart from SELINUX is not claimed, supported
+        * by selinux.
+        */
+       return -EOPNOTSUPP;
+}
+
 /* file security operations */
 
 static int selinux_revalidate_file_permission(struct file *file, int mask)
@@ -6109,6 +6124,7 @@ static struct security_hook_list selinux_hooks[] = {
        LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
        LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
        LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
+       LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
 
        LSM_HOOK_INIT(file_permission, selinux_file_permission),
        LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),