Re: [PATCH 07/15] flask: unify {get, set}vcpucontext permissions

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Thu, Jun 09, 2016 at 10:47:10AM -0400, Daniel De Graaf wrote:
> These permissions were initially split because they were in separate
> domctls, but this split is very unlikely to actually provide security
> benefits: it would require a carefully contrived situation for a domain
> to both need access to one type of CPU register and also need to be
> prohibited from accessing another type.
> 

CC-ing Andrew as I believe has been looking in this code when doing
miration and may have an opinion on this.

> Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
>  tools/flask/policy/modules/dom0.te  |  1 -
>  tools/flask/policy/modules/xen.if   |  7 +++----
>  xen/xsm/flask/hooks.c               | 20 ++++++--------------
>  xen/xsm/flask/policy/access_vectors | 16 ++++++----------
>  4 files changed, 15 insertions(+), 29 deletions(-)
> 
> diff --git a/tools/flask/policy/modules/dom0.te b/tools/flask/policy/modules/dom0.te
> index ef6a986..d228b24 100644
> --- a/tools/flask/policy/modules/dom0.te
> +++ b/tools/flask/policy/modules/dom0.te
> @@ -34,7 +34,6 @@ allow dom0_t dom0_t:domain {
>  	setvcpucontext max_vcpus setaffinity getaffinity getscheduler
>  	getdomaininfo getvcpuinfo getvcpucontext setdomainmaxmem setdomainhandle
>  	setdebugging hypercall settime setaddrsize getaddrsize trigger
> -	getextvcpucontext setextvcpucontext getvcpuextstate setvcpuextstate
>  	getpodtarget setpodtarget set_misc_info set_virq_handler
>  };
>  allow dom0_t dom0_t:domain2 {
> diff --git a/tools/flask/policy/modules/xen.if b/tools/flask/policy/modules/xen.if
> index 00d1bbb..fd96303 100644
> --- a/tools/flask/policy/modules/xen.if
> +++ b/tools/flask/policy/modules/xen.if
> @@ -47,9 +47,8 @@ define(`declare_build_label', `
>  
>  define(`create_domain_common', `
>  	allow $1 $2:domain { create max_vcpus setdomainmaxmem setaddrsize
> -			getdomaininfo hypercall setvcpucontext setextvcpucontext
> -			getscheduler getvcpuinfo getvcpuextstate getaddrsize
> -			getaffinity setaffinity setvcpuextstate };
> +			getdomaininfo hypercall setvcpucontext getscheduler
> +			getvcpuinfo getaddrsize getaffinity setaffinity };
>  	allow $1 $2:domain2 { set_cpuid settsc setscheduler setclaim
>  			set_max_evtchn set_vnumainfo get_vnumainfo cacheflush
>  			psr_cmt_op psr_cat_op soft_reset };
> @@ -94,7 +93,7 @@ define(`migrate_domain_out', `
>  	allow $1 domxen_t:mmu map_read;
>  	allow $1 $2:hvm { gethvmc getparam irqlevel };
>  	allow $1 $2:mmu { stat pageinfo map_read };
> -	allow $1 $2:domain { getaddrsize getvcpucontext getextvcpucontext getvcpuextstate pause destroy };
> +	allow $1 $2:domain { getaddrsize getvcpucontext pause destroy };
>  	allow $1 $2:domain2 gettsc;
>  	allow $1 $2:shadow { enable disable logdirty };
>  ')
> diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
> index 20d46c8..a8d45e7 100644
> --- a/xen/xsm/flask/hooks.c
> +++ b/xen/xsm/flask/hooks.c
> @@ -630,10 +630,16 @@ static int flask_domctl(struct domain *d, int cmd)
>      case XEN_DOMCTL_setdomainhandle:
>          return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SETDOMAINHANDLE);
>  
> +    case XEN_DOMCTL_set_ext_vcpucontext:
> +    case XEN_DOMCTL_set_vcpu_msrs:
>      case XEN_DOMCTL_setvcpucontext:
> +    case XEN_DOMCTL_setvcpuextstate:
>          return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SETVCPUCONTEXT);
>  
> +    case XEN_DOMCTL_get_ext_vcpucontext:
> +    case XEN_DOMCTL_get_vcpu_msrs:
>      case XEN_DOMCTL_getvcpucontext:
> +    case XEN_DOMCTL_getvcpuextstate:
>          return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__GETVCPUCONTEXT);
>  
>      case XEN_DOMCTL_getvcpuinfo:
> @@ -675,20 +681,6 @@ static int flask_domctl(struct domain *d, int cmd)
>      case XEN_DOMCTL_pin_mem_cacheattr:
>          return current_has_perm(d, SECCLASS_HVM, HVM__CACHEATTR);
>  
> -    case XEN_DOMCTL_set_ext_vcpucontext:
> -    case XEN_DOMCTL_set_vcpu_msrs:
> -        return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SETEXTVCPUCONTEXT);
> -
> -    case XEN_DOMCTL_get_ext_vcpucontext:
> -    case XEN_DOMCTL_get_vcpu_msrs:
> -        return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__GETEXTVCPUCONTEXT);
> -
> -    case XEN_DOMCTL_setvcpuextstate:
> -        return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SETVCPUEXTSTATE);
> -
> -    case XEN_DOMCTL_getvcpuextstate:
> -        return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__GETVCPUEXTSTATE);
> -
>      case XEN_DOMCTL_sendtrigger:
>          return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__TRIGGER);
>  
> diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors
> index 3d29042..7e69ede 100644
> --- a/xen/xsm/flask/policy/access_vectors
> +++ b/xen/xsm/flask/policy/access_vectors
> @@ -111,6 +111,9 @@ class xen2
>  class domain
>  {
>  # XEN_DOMCTL_setvcpucontext
> +# XEN_DOMCTL_setvcpuextstate
> +# XEN_DOMCTL_set_ext_vcpucontext
> +# XEN_DOMCTL_set_vcpu_msrs
>      setvcpucontext
>  # XEN_DOMCTL_pausedomain
>      pause
> @@ -142,6 +145,9 @@ class domain
>  # XEN_DOMCTL_getvcpuinfo
>      getvcpuinfo
>  # XEN_DOMCTL_getvcpucontext
> +# XEN_DOMCTL_get_ext_vcpucontext
> +# XEN_DOMCTL_getvcpuextstate
> +# XEN_DOMCTL_get_vcpu_msrs
>      getvcpucontext
>  # XEN_DOMCTL_max_mem
>      setdomainmaxmem
> @@ -166,16 +172,6 @@ class domain
>      getaddrsize
>  # XEN_DOMCTL_sendtrigger
>      trigger
> -# XEN_DOMCTL_get_ext_vcpucontext
> -# XEN_DOMCTL_set_vcpu_msrs
> -    getextvcpucontext
> -# XEN_DOMCTL_set_ext_vcpucontext
> -# XEN_DOMCTL_get_vcpu_msrs
> -    setextvcpucontext
> -# XEN_DOMCTL_getvcpuextstate
> -    getvcpuextstate
> -# XEN_DOMCTL_setvcpuextstate
> -    setvcpuextstate
>  # XENMEM_get_pod_target
>      getpodtarget
>  # XENMEM_set_pod_target
> -- 
> 2.5.5
> 
> 
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