diff mbox series

[v2,1/2] common: map_vcpu_info() cosmetics

Message ID 29514f9a-b630-f66e-286e-8b73fcf4d58a@suse.com (mailing list archive)
State New, archived
Headers show
Series common: XSA-327 follow-up | expand

Commit Message

Jan Beulich Dec. 22, 2020, 8:14 a.m. UTC 
Use ENXIO instead of EINVAL to cover the two cases of the address not
satisfying the requirements. This will make an issue here better stand
out at the call site.

Also add a missing compat-mode related size check: If the sizes
differed, other code in the function would need changing. Accompany this
by a change to the initial sizeof() expression, tying it to the type of
the variable we're actually after (matching e.g. the alignof() added by
XSA-327).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Comments

Julien Grall April 1, 2021, 4:02 p.m. UTC | #1 
Hi Jan,

On 22/12/2020 08:14, Jan Beulich wrote:
> Use ENXIO instead of EINVAL to cover the two cases of the address not
> satisfying the requirements. This will make an issue here better stand
> out at the call site.
> 
> Also add a missing compat-mode related size check: If the sizes
> differed, other code in the function would need changing. Accompany this
> by a change to the initial sizeof() expression, tying it to the type of
> the variable we're actually after (matching e.g. the alignof() added by
> XSA-327).
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Acked-by: Julien Grall <jgrall@amazon.com>

Cheers,
diff mbox series

Patch

--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1241,17 +1241,18 @@  int map_vcpu_info(struct vcpu *v, unsign
     struct page_info *page;
     unsigned int align;
 
-    if ( offset > (PAGE_SIZE - sizeof(vcpu_info_t)) )
-        return -EINVAL;
+    if ( offset > (PAGE_SIZE - sizeof(*new_info)) )
+        return -ENXIO;
 
 #ifdef CONFIG_COMPAT
+    BUILD_BUG_ON(sizeof(*new_info) != sizeof(new_info->compat));
     if ( has_32bit_shinfo(d) )
         align = alignof(new_info->compat);
     else
 #endif
         align = alignof(*new_info);
     if ( offset & (align - 1) )
-        return -EINVAL;
+        return -ENXIO;
 
     if ( !mfn_eq(v->vcpu_info_mfn, INVALID_MFN) )
         return -EINVAL;