[PATCH] selinux: MLS compatibility

This patch enables files created on a MLS-enabled SELinux system to be
accessible on a non-MLS SELinux system, by skipping the MLS component of
the security context in the non-MLS case.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by:  James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index aaefac2..640d0bf 100644 (file)
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -262,8 +262,11 @@ int mls_context_to_sid(char oldc,
        struct cat_datum *catdatum, *rngdatum;
        int l, rc = -EINVAL;
 
-       if (!selinux_mls_enabled)
+       if (!selinux_mls_enabled) {
+               if (def_sid != SECSID_NULL && oldc)
+                       *scontext += strlen(*scontext);
                return 0;
+       }
 
        /*
         * No MLS component to the security context, try and map to