Fix CVE-2025-24855 (RHEL-83492)

Resolves: RHEL-83492

libxslt-1.1.32-CVE-2025-24855.patch

@@ -0,0 +1,130 @@
+From c7c7f1f78dd202a053996fcefe57eb994aec8ef2 Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Tue, 17 Dec 2024 15:56:21 +0100
+Subject: [PATCH] [CVE-2025-24855] Fix use-after-free of XPath context node
+
+There are several places where the XPath context node isn't restored
+after modifying it, leading to use-after-free errors with nested XPath
+evaluations and dynamically allocated context nodes.
+
+Restore XPath context node in
+
+- xsltNumberFormatGetValue
+- xsltEvalXPathPredicate
+- xsltEvalXPathStringNs
+- xsltComputeSortResultInternal
+
+In some places, the transformation context node was saved and restored
+which shouldn't be necessary.
+
+Thanks to Ivan Fratric for the report!
+
+Fixes #128.
+---
+ libxslt/numbers.c   | 5 +++++
+ libxslt/templates.c | 9 ++++++---
+ libxslt/xsltutils.c | 4 ++--
+ 3 files changed, 13 insertions(+), 5 deletions(-)
+
+diff --git a/libxslt/numbers.c b/libxslt/numbers.c
+index 0e1fa136..741124d1 100644
+--- a/libxslt/numbers.c
++++ b/libxslt/numbers.c
+@@ -733,9 +733,12 @@ xsltNumberFormatGetValue(xmlXPathContextPtr context,
+     int amount = 0;
+     xmlBufferPtr pattern;
+     xmlXPathObjectPtr obj;
++    xmlNodePtr oldNode;
+ 
+     pattern = xmlBufferCreate();
+     if (pattern != NULL) {
++        oldNode = context->node;
++
+ 	xmlBufferCCat(pattern, "number(");
+ 	xmlBufferCat(pattern, value);
+ 	xmlBufferCCat(pattern, ")");
+@@ -748,6 +751,8 @@ xsltNumberFormatGetValue(xmlXPathContextPtr context,
+ 	    xmlXPathFreeObject(obj);
+ 	}
+ 	xmlBufferFree(pattern);
++
++        context->node = oldNode;
+     }
+     return amount;
+ }
+diff --git a/libxslt/templates.c b/libxslt/templates.c
+index f08b9bda..1c8d96e2 100644
+--- a/libxslt/templates.c
++++ b/libxslt/templates.c
+@@ -61,6 +61,7 @@ xsltEvalXPathPredicate(xsltTransformContextPtr ctxt, xmlXPathCompExprPtr comp,
+     int oldNsNr;
+     xmlNsPtr *oldNamespaces;
+     xmlNodePtr oldInst;
++    xmlNodePtr oldNode;
+     int oldProximityPosition, oldContextSize;
+ 
+     if ((ctxt == NULL) || (ctxt->inst == NULL)) {
+@@ -69,6 +70,7 @@ xsltEvalXPathPredicate(xsltTransformContextPtr ctxt, xmlXPathCompExprPtr comp,
+         return(0);
+     }
+ 
++    oldNode = ctxt->xpathCtxt->node;
+     oldContextSize = ctxt->xpathCtxt->contextSize;
+     oldProximityPosition = ctxt->xpathCtxt->proximityPosition;
+     oldNsNr = ctxt->xpathCtxt->nsNr;
+@@ -96,8 +98,9 @@ xsltEvalXPathPredicate(xsltTransformContextPtr ctxt, xmlXPathCompExprPtr comp,
+ 	ctxt->state = XSLT_STATE_STOPPED;
+ 	ret = 0;
+     }
+-    ctxt->xpathCtxt->nsNr = oldNsNr;
+ 
++    ctxt->xpathCtxt->node = oldNode;
++    ctxt->xpathCtxt->nsNr = oldNsNr;
+     ctxt->xpathCtxt->namespaces = oldNamespaces;
+     ctxt->inst = oldInst;
+     ctxt->xpathCtxt->contextSize = oldContextSize;
+@@ -137,7 +140,7 @@ xsltEvalXPathStringNs(xsltTransformContextPtr ctxt, xmlXPathCompExprPtr comp,
+     }
+ 
+     oldInst = ctxt->inst;
+-    oldNode = ctxt->node;
++    oldNode = ctxt->xpathCtxt->node;
+     oldPos = ctxt->xpathCtxt->proximityPosition;
+     oldSize = ctxt->xpathCtxt->contextSize;
+     oldNsNr = ctxt->xpathCtxt->nsNr;
+@@ -167,7 +170,7 @@ xsltEvalXPathStringNs(xsltTransformContextPtr ctxt, xmlXPathCompExprPtr comp,
+ 	 "xsltEvalXPathString: returns %s\n", ret));
+ #endif
+     ctxt->inst = oldInst;
+-    ctxt->node = oldNode;
++    ctxt->xpathCtxt->node = oldNode;
+     ctxt->xpathCtxt->contextSize = oldSize;
+     ctxt->xpathCtxt->proximityPosition = oldPos;
+     ctxt->xpathCtxt->nsNr = oldNsNr;
+diff --git a/libxslt/xsltutils.c b/libxslt/xsltutils.c
+index 0e9dc62f..a20da961 100644
+--- a/libxslt/xsltutils.c
++++ b/libxslt/xsltutils.c
+@@ -1065,8 +1065,8 @@ xsltComputeSortResultInternal(xsltTransformContextPtr ctxt, xmlNodePtr sort,
+ 	return(NULL);
+     }
+ 
+-    oldNode = ctxt->node;
+     oldInst = ctxt->inst;
++    oldNode = ctxt->xpathCtxt->node;
+     oldPos = ctxt->xpathCtxt->proximityPosition;
+     oldSize = ctxt->xpathCtxt->contextSize;
+     oldNsNr = ctxt->xpathCtxt->nsNr;
+@@ -1137,8 +1137,8 @@ xsltComputeSortResultInternal(xsltTransformContextPtr ctxt, xmlNodePtr sort,
+ 	    results[i] = NULL;
+ 	}
+     }
+-    ctxt->node = oldNode;
+     ctxt->inst = oldInst;
++    ctxt->xpathCtxt->node = oldNode;
+     ctxt->xpathCtxt->contextSize = oldSize;
+     ctxt->xpathCtxt->proximityPosition = oldPos;
+     ctxt->xpathCtxt->nsNr = oldNsNr;
+-- 
+GitLab
+

libxslt.spec

@@ -35,6 +35,8 @@ Patch4:         libxslt-1.1.32-CVE-2019-11068.patch
 Patch5:         libxslt-1.1.32-unexpected-rvt-flag.patch
 # https://issues.redhat.com/browse/RHEL-83506
 Patch6:         libxslt-1.1.32-CVE-2024-55549.patch
+# https://issues.redhat.com/browse/RHEL-83492
+Patch7:         libxslt-1.1.32-CVE-2025-24855.patch
 
 %description
 This C library allows to transform XML files into other XML files
@@ -141,6 +143,7 @@ rm -vrf %{buildroot}%{_docdir}
 %changelog
 * Fri Apr 04 2025 David King <dking@redhat.com> - 1.1.32-6.1
 - Fix CVE-2024-55549 (RHEL-83506)
+- Fix CVE-2025-24855 (RHEL-83492)
 
 * Mon Aug 24 2020 David King <dking@redhat.com> - 1.1.32-6
 - Fix unexpected RVT flag error (#1860467)