diff mbox series

[v3,2/2] x86: validate VM assist value in arch_set_info_guest()

Message ID 60f51e40-ada5-b206-cfd3-d1cc1d24c382@suse.com (mailing list archive)
State New, archived
Headers show
Series x86: VM assist hypercall adjustments | expand

Commit Message

Jan Beulich April 21, 2020, 2:39 p.m. UTC 
While I can't spot anything that would go wrong, just like the
respective hypercall only permits applicable bits to be set, we should
also do so when loading guest context.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
I'd like to note that Arm lacks a field to save/restore vm_assist.
diff mbox series

Patch

--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -932,6 +932,9 @@  int arch_set_info_guest(
         }
     }
 
+    if ( v->vcpu_id == 0 && (c(vm_assist) & ~arch_vm_assist_valid_mask(d)) )
+        return -EINVAL;
+
     if ( is_hvm_domain(d) )
     {
         for ( i = 0; i < ARRAY_SIZE(v->arch.dr); ++i )