[Xen-changelog] [xen master] domctl: tighten XEN_DOMCTL_*_permission

[patchbot@xxxxxxx]

commit b27b47b0b38b336226ba390f3cf74d66c21905ed
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu May 8 13:57:12 2014 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu May 8 13:57:12 2014 +0200

    domctl: tighten XEN_DOMCTL_*_permission
    
    With proper permission (and, for the I/O port case, wrap-around) checks
    added (note that for the I/O port case a count of zero is now being
    disallowed, in line with I/O memory handling):
    
    XEN_DOMCTL_irq_permission:
    XEN_DOMCTL_ioport_permission:
    
     Of both IRQs and I/O ports there is only a reasonably small amount, so
     there's no excess resource consumption involved here. Additionally
     they both have a specialized XSM hook associated.
    
    XEN_DOMCTL_iomem_permission:
    
     While this also has a specialized XSM hook associated (just like
     XEN_DOMCTL_{irq,ioport}_permission), it's not clear whether it's
     reasonable to expect XSM to restrict the number of ranges associated
     with a domain via this hook (which is the main resource consumption
     item here).
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Tim Deegan <tim@xxxxxxx>
---
 docs/misc/xsm-flask.txt |    2 --
 xen/arch/x86/domctl.c   |   15 +++++++--------
 xen/common/domctl.c     |    7 +++++--
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/docs/misc/xsm-flask.txt b/docs/misc/xsm-flask.txt
index d06983c..31b9d27 100644
--- a/docs/misc/xsm-flask.txt
+++ b/docs/misc/xsm-flask.txt
@@ -72,9 +72,7 @@ __HYPERVISOR_domctl (xen/include/public/domctl.h)
  * XEN_DOMCTL_getvcpucontext
  * XEN_DOMCTL_max_vcpus
  * XEN_DOMCTL_scheduler_op
- * XEN_DOMCTL_irq_permission
  * XEN_DOMCTL_iomem_permission
- * XEN_DOMCTL_ioport_permission
  * XEN_DOMCTL_gethvmcontext
  * XEN_DOMCTL_sethvmcontext
  * XEN_DOMCTL_set_address_size
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index d792e87..fbdc8e6 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -46,6 +46,8 @@ static int gdbsx_guest_mem_io(
     return (iop->remain ? -EFAULT : 0);
 }
 
+#define MAX_IOPORTS 0x10000
+
 long arch_do_domctl(
     struct xen_domctl *domctl, struct domain *d,
     XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
@@ -72,13 +74,11 @@ long arch_do_domctl(
         unsigned int np = domctl->u.ioport_permission.nr_ports;
         int allow = domctl->u.ioport_permission.allow_access;
 
-        ret = -EINVAL;
-        if ( (fp + np) > 65536 )
-            break;
-
-        if ( np == 0 )
-            ret = 0;
-        else if ( xsm_ioport_permission(XSM_HOOK, d, fp, fp + np - 1, allow) )
+        if ( (fp + np) <= fp || (fp + np) > MAX_IOPORTS )
+            ret = -EINVAL;
+        else if ( !ioports_access_permitted(current->domain,
+                                            fp, fp + np - 1) ||
+                  xsm_ioport_permission(XSM_HOOK, d, fp, fp + np - 1, allow) )
             ret = -EPERM;
         else if ( allow )
             ret = ioports_permit_access(d, fp, fp + np - 1);
@@ -719,7 +719,6 @@ long arch_do_domctl(
 
     case XEN_DOMCTL_ioport_mapping:
     {
-#define MAX_IOPORTS    0x10000
         struct hvm_iommu *hd;
         unsigned int fgp = domctl->u.ioport_mapping.first_gport;
         unsigned int fmp = domctl->u.ioport_mapping.first_mport;
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index af3614b..2ba5daa 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -790,7 +790,8 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
 
         if ( pirq >= d->nr_pirqs )
             ret = -EINVAL;
-        else if ( xsm_irq_permission(XSM_HOOK, d, pirq, allow) )
+        else if ( !pirq_access_permitted(current->domain, pirq) ||
+                  xsm_irq_permission(XSM_HOOK, d, pirq, allow) )
             ret = -EPERM;
         else if ( allow )
             ret = pirq_permit_access(d, pirq);
@@ -809,7 +810,9 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
         if ( (mfn + nr_mfns - 1) < mfn ) /* wrap? */
             break;
 
-        if ( xsm_iomem_permission(XSM_HOOK, d, mfn, mfn + nr_mfns - 1, allow) )
+        if ( !iomem_access_permitted(current->domain,
+                                     mfn, mfn + nr_mfns - 1) ||
+             xsm_iomem_permission(XSM_HOOK, d, mfn, mfn + nr_mfns - 1, allow) )
             ret = -EPERM;
         else if ( allow )
             ret = iomem_permit_access(d, mfn, mfn + nr_mfns - 1);
--
generated by git-patchbot for /home/xen/git/xen.git#master

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