From: Michal Privoznik <mprivozn@redhat.com>
Date: Tue, 4 Nov 2025 10:03:18 +0000 (+0100)
Subject: domain_capabilities: Use virXMLFormatElement() in FORMAT_PROLOGUE and FORMAT_EPILOGUE... 
X-Git-Tag: CVE-2025-12748~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf34b3c86ffdc42bd5fa9ecb36e57391459f5572;p=thirdparty%2Flibvirt.git

domain_capabilities: Use virXMLFormatElement() in FORMAT_PROLOGUE and FORMAT_EPILOGUE macros

Domain capabilities XML is formatted (mostly) using
FORMAT_PROLOGUE and FORMAT_EPILOGUE macros. These format opening
and closing stanzas for given element. The FORMAT_PROLOGUE macro
even tries to be clever and format element onto one line (if the
element isn't supported), but that's not enough. Fortunately, we
have virXMLFormatElement() which formats elements properly, so
let's switch macros into using that.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
---

diff --git a/src/conf/domain_capabilities.c b/src/conf/domain_capabilities.c
index 78a5b1f56a..f843124695 100644
--- a/src/conf/domain_capabilities.c
+++ b/src/conf/domain_capabilities.c
@@ -373,27 +373,38 @@ virDomainCapsStringValuesFormat(virBuffer *buf,
 }
 
 
+/**
+ * FORMAT_PROLOGUE:
+ * @item: item to format
+ *
+ * Formats part of domain capabilities for @item. The element name is #item so
+ * variable name is important. If the particular capability is not supported,
+ * then the macro also returns early.
+ *
+ * Additionally, the macro declares two variables: @childBuf and @attrBuf where
+ * the former holds contents of the child elements and the latter holds
+ * contents of <#item/> attributes (so far limited to "supported='yes/no'").
+ */
 #define FORMAT_PROLOGUE(item) \
+    g_auto(virBuffer) childBuf = VIR_BUFFER_INIT_CHILD(buf); \
+    g_auto(virBuffer) attrBuf = VIR_BUFFER_INITIALIZER; \
     do { \
         if (!item || item->supported == VIR_TRISTATE_BOOL_ABSENT) \
             return; \
-        virBufferAsprintf(buf, "<" #item " supported='%s'%s\n", \
-                (item->supported == VIR_TRISTATE_BOOL_YES) ? "yes" : "no", \
-                (item->supported == VIR_TRISTATE_BOOL_YES) ? ">" : "/>"); \
-        if (item->supported == VIR_TRISTATE_BOOL_NO) \
+        virBufferAsprintf(&attrBuf, " supported='%s'", \
+                          (item->supported == VIR_TRISTATE_BOOL_YES) ? "yes" : "no"); \
+        if (item->supported == VIR_TRISTATE_BOOL_NO) { \
+            virXMLFormatElement(buf, #item, &attrBuf, NULL); \
             return; \
-        virBufferAdjustIndent(buf, 2); \
+        } \
     } while (0)
 
 #define FORMAT_EPILOGUE(item) \
-    do { \
-        virBufferAdjustIndent(buf, -2); \
-        virBufferAddLit(buf, "</" #item ">\n"); \
-    } while (0)
+    virXMLFormatElement(buf, #item, &attrBuf, &childBuf)
 
 #define ENUM_PROCESS(master, capsEnum, valToStr) \
     do { \
-        virDomainCapsEnumFormat(buf, &master->capsEnum, \
+        virDomainCapsEnumFormat(&childBuf, &master->capsEnum, \
                                 #capsEnum, valToStr); \
     } while (0)
 
@@ -417,7 +428,7 @@ virDomainCapsLoaderFormat(virBuffer *buf,
 {
     FORMAT_PROLOGUE(loader);
 
-    virDomainCapsStringValuesFormat(buf, &loader->values);
+    virDomainCapsStringValuesFormat(&childBuf, &loader->values);
     ENUM_PROCESS(loader, type, virDomainLoaderTypeToString);
     ENUM_PROCESS(loader, readonly, virTristateBoolTypeToString);
     ENUM_PROCESS(loader, secure, virTristateBoolTypeToString);
@@ -435,7 +446,7 @@ virDomainCapsOSFormat(virBuffer *buf,
 
     ENUM_PROCESS(os, firmware, virDomainOsDefFirmwareTypeToString);
 
-    virDomainCapsLoaderFormat(buf, loader);
+    virDomainCapsLoaderFormat(&childBuf, loader);
 
     FORMAT_EPILOGUE(os);
 }
@@ -851,7 +862,7 @@ virDomainCapsFeatureHypervFormat(virBuffer *buf,
         virBufferEscapeString(&defaults, "<vendor_id>%s</vendor_id>\n", hyperv->vendor_id);
     }
 
-    virXMLFormatElement(buf, "defaults", NULL, &defaults);
+    virXMLFormatElement(&childBuf, "defaults", NULL, &defaults);
 
     FORMAT_EPILOGUE(hyperv);
 }
diff --git a/tests/domaincapsdata/bhyve_basic.x86_64.xml b/tests/domaincapsdata/bhyve_basic.x86_64.xml
index 2dee7c6547..44527bbb7f 100644
--- a/tests/domaincapsdata/bhyve_basic.x86_64.xml
+++ b/tests/domaincapsdata/bhyve_basic.x86_64.xml
@@ -26,8 +26,7 @@
     </disk>
     <graphics supported='no'/>
     <video supported='no'/>
-    <hostdev supported='yes'>
-    </hostdev>
+    <hostdev supported='yes'/>
     <console supported='yes'>
       <enum name='type'>
         <value>tcp</value>
diff --git a/tests/domaincapsdata/bhyve_fbuf.x86_64.xml b/tests/domaincapsdata/bhyve_fbuf.x86_64.xml
index d2f0dd6383..5b2044736c 100644
--- a/tests/domaincapsdata/bhyve_fbuf.x86_64.xml
+++ b/tests/domaincapsdata/bhyve_fbuf.x86_64.xml
@@ -43,8 +43,7 @@
         <value>gop</value>
       </enum>
     </video>
-    <hostdev supported='yes'>
-    </hostdev>
+    <hostdev supported='yes'/>
     <console supported='yes'>
       <enum name='type'>
         <value>tcp</value>
diff --git a/tests/domaincapsdata/bhyve_uefi.x86_64.xml b/tests/domaincapsdata/bhyve_uefi.x86_64.xml
index b093358c49..d99dde98e1 100644
--- a/tests/domaincapsdata/bhyve_uefi.x86_64.xml
+++ b/tests/domaincapsdata/bhyve_uefi.x86_64.xml
@@ -35,8 +35,7 @@
     </disk>
     <graphics supported='no'/>
     <video supported='no'/>
-    <hostdev supported='yes'>
-    </hostdev>
+    <hostdev supported='yes'/>
     <console supported='yes'>
       <enum name='type'>
         <value>tcp</value>