[PATCH] selinux: make mls_compute_sid always polyinstantiate

[PATCH] selinux: make mls_compute_sid always polyinstantiate

[Eamon Walsh]

This patch removes the requirement that the new and related object types 
differ in order to polyinstantiate by MLS level.  This allows MLS 
polyinstantiation to occur in the absence of explicit type_member rules 
or when the type has not changed.

Potential users of this support include pam_namespace.so (directory 
polyinstantiation) and the SELinux X support (property polyinstantiation).

Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
---

 mls.c |   11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)


diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index fb5d70a..3bbcb53 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -537,15 +537,8 @@ int mls_compute_sid(struct context *scontext,
 			/* Use the process effective MLS attributes. */
 			return mls_context_cpy_low(newcontext, scontext);
 	case AVTAB_MEMBER:
-		/* Only polyinstantiate the MLS attributes if
-		   the type is being polyinstantiated */
-		if (newcontext->type != tcontext->type) {
-			/* Use the process effective MLS attributes. */
-			return mls_context_cpy_low(newcontext, scontext);
-		} else {
-			/* Use the related object MLS attributes. */
-			return mls_context_cpy(newcontext, tcontext);
-		}
+		/* Use the process effective MLS attributes. */
+		return mls_context_cpy_low(newcontext, scontext);
 	default:
 		return -EINVAL;
 	}



-- 
Eamon Walsh <ewalsh@tycho.nsa.gov>
National Security Agency

Re: [PATCH] selinux: make mls_compute_sid always polyinstantiate

[Stephen Smalley]

On Thu, 2008-01-24 at 15:30 -0500, Eamon Walsh wrote:
> This patch removes the requirement that the new and related object types 
> differ in order to polyinstantiate by MLS level.  This allows MLS 
> polyinstantiation to occur in the absence of explicit type_member rules 
> or when the type has not changed.
> 
> Potential users of this support include pam_namespace.so (directory 
> polyinstantiation) and the SELinux X support (property polyinstantiation).
> 
> Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>

Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>

> ---
> 
>  mls.c |   11 ++---------
>  1 file changed, 2 insertions(+), 9 deletions(-)

(nit:  use diffstat -p1 in the future)

> 
> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
> index fb5d70a..3bbcb53 100644
> --- a/security/selinux/ss/mls.c
> +++ b/security/selinux/ss/mls.c
> @@ -537,15 +537,8 @@ int mls_compute_sid(struct context *scontext,
>  			/* Use the process effective MLS attributes. */
>  			return mls_context_cpy_low(newcontext, scontext);
>  	case AVTAB_MEMBER:
> -		/* Only polyinstantiate the MLS attributes if
> -		   the type is being polyinstantiated */
> -		if (newcontext->type != tcontext->type) {
> -			/* Use the process effective MLS attributes. */
> -			return mls_context_cpy_low(newcontext, scontext);
> -		} else {
> -			/* Use the related object MLS attributes. */
> -			return mls_context_cpy(newcontext, tcontext);
> -		}
> +		/* Use the process effective MLS attributes. */
> +		return mls_context_cpy_low(newcontext, scontext);
>  	default:
>  		return -EINVAL;
>  	}
> 
> 
> 
-- 
Stephen Smalley
National Security Agency

Re: [PATCH] selinux: make mls_compute_sid always polyinstantiate

[Joshua Brindle]

Eamon Walsh wrote:
> This patch removes the requirement that the new and related object 
> types differ in order to polyinstantiate by MLS level.  This allows 
> MLS polyinstantiation to occur in the absence of explicit type_member 
> rules or when the type has not changed.
>
> Potential users of this support include pam_namespace.so (directory 
> polyinstantiation) and the SELinux X support (property 
> polyinstantiation).
>
> Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
> ---
>
> mls.c |   11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
>
> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
> index fb5d70a..3bbcb53 100644
> --- a/security/selinux/ss/mls.c
> +++ b/security/selinux/ss/mls.c
> @@ -537,15 +537,8 @@ int mls_compute_sid(struct context *scontext,
>             /* Use the process effective MLS attributes. */
>             return mls_context_cpy_low(newcontext, scontext);
>     case AVTAB_MEMBER:
> -        /* Only polyinstantiate the MLS attributes if
> -           the type is being polyinstantiated */
> -        if (newcontext->type != tcontext->type) {
> -            /* Use the process effective MLS attributes. */
> -            return mls_context_cpy_low(newcontext, scontext);
> -        } else {
> -            /* Use the related object MLS attributes. */
> -            return mls_context_cpy(newcontext, tcontext);
> -        }
> +        /* Use the process effective MLS attributes. */
> +        return mls_context_cpy_low(newcontext, scontext);
>     default:
>         return -EINVAL;
>     }

Should there be a patch to update mls.c in libsepol as well? I hope we 
are keeping the kss and uss in sync.

Re: [PATCH] selinux: make mls_compute_sid always polyinstantiate

[James Morris]

On Thu, 24 Jan 2008, Eamon Walsh wrote:

> This patch removes the requirement that the new and related object types
> differ in order to polyinstantiate by MLS level.  This allows MLS
> polyinstantiation to occur in the absence of explicit type_member rules or
> when the type has not changed.
> 
> Potential users of this support include pam_namespace.so (directory
> polyinstantiation) and the SELinux X support (property polyinstantiation).
> 
> Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>

Applied to 
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm

-- 
James Morris
<jmorris@namei.org>

Re: [PATCH] selinux: make mls_compute_sid always polyinstantiate

[Xavier Toth]

Is this in rawhide, if not when will it be?

On Thu, Jan 24, 2008 at 2:30 PM, Eamon Walsh <ewalsh@tycho.nsa.gov> wrote:
> This patch removes the requirement that the new and related object types
>  differ in order to polyinstantiate by MLS level.  This allows MLS
>  polyinstantiation to occur in the absence of explicit type_member rules
>  or when the type has not changed.
>
>  Potential users of this support include pam_namespace.so (directory
>  polyinstantiation) and the SELinux X support (property polyinstantiation).
>
>  Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
>  ---
>
>   mls.c |   11 ++---------
>   1 file changed, 2 insertions(+), 9 deletions(-)
>
>
>  diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
>  index fb5d70a..3bbcb53 100644
>  --- a/security/selinux/ss/mls.c
>  +++ b/security/selinux/ss/mls.c
>  @@ -537,15 +537,8 @@ int mls_compute_sid(struct context *scontext,
>                         /* Use the process effective MLS attributes. */
>                         return mls_context_cpy_low(newcontext, scontext);
>         case AVTAB_MEMBER:
>  -               /* Only polyinstantiate the MLS attributes if
>  -                  the type is being polyinstantiated */
>  -               if (newcontext->type != tcontext->type) {
>  -                       /* Use the process effective MLS attributes. */
>  -                       return mls_context_cpy_low(newcontext, scontext);
>  -               } else {
>  -                       /* Use the related object MLS attributes. */
>  -                       return mls_context_cpy(newcontext, tcontext);
>  -               }
>  +               /* Use the process effective MLS attributes. */
>  +               return mls_context_cpy_low(newcontext, scontext);
>         default:
>                 return -EINVAL;
>         }
>
>
>
>  --
>  Eamon Walsh <ewalsh@tycho.nsa.gov>
>  National Security Agency
>
>
>  --
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