You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
54 lines
1.8 KiB
54 lines
1.8 KiB
From a436374994c47b12d5de1b8b1d191a098fa23594 Mon Sep 17 00:00:00 2001
|
|
From: Nick Wellnhofer <wellnhofer@aevum.de>
|
|
Date: Mon, 30 Jul 2018 12:54:38 +0200
|
|
Subject: [PATCH 12/13] Fix nullptr deref with XPath logic ops
|
|
|
|
If the XPath stack is corrupted, for example by a misbehaving extension
|
|
function, the "and" and "or" XPath operators could dereference NULL
|
|
pointers. Check that the XPath stack isn't empty and optimize the
|
|
logic operators slightly.
|
|
|
|
Closes: https://gitlab.gnome.org/GNOME/libxml2/issues/5
|
|
|
|
Also see
|
|
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901817
|
|
https://bugzilla.redhat.com/show_bug.cgi?id=1595985
|
|
|
|
This is CVE-2018-14404.
|
|
|
|
Thanks to Guy Inbar for the report.
|
|
---
|
|
xpath.c | 10 ++++------
|
|
1 file changed, 4 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/xpath.c b/xpath.c
|
|
index 3fae0bf4..5e3bb9ff 100644
|
|
--- a/xpath.c
|
|
+++ b/xpath.c
|
|
@@ -13297,9 +13297,8 @@ xmlXPathCompOpEval(xmlXPathParserContextPtr ctxt, xmlXPathStepOpPtr op)
|
|
return(0);
|
|
}
|
|
xmlXPathBooleanFunction(ctxt, 1);
|
|
- arg1 = valuePop(ctxt);
|
|
- arg1->boolval &= arg2->boolval;
|
|
- valuePush(ctxt, arg1);
|
|
+ if (ctxt->value != NULL)
|
|
+ ctxt->value->boolval &= arg2->boolval;
|
|
xmlXPathReleaseObject(ctxt->context, arg2);
|
|
return (total);
|
|
case XPATH_OP_OR:
|
|
@@ -13323,9 +13322,8 @@ xmlXPathCompOpEval(xmlXPathParserContextPtr ctxt, xmlXPathStepOpPtr op)
|
|
return(0);
|
|
}
|
|
xmlXPathBooleanFunction(ctxt, 1);
|
|
- arg1 = valuePop(ctxt);
|
|
- arg1->boolval |= arg2->boolval;
|
|
- valuePush(ctxt, arg1);
|
|
+ if (ctxt->value != NULL)
|
|
+ ctxt->value->boolval |= arg2->boolval;
|
|
xmlXPathReleaseObject(ctxt->context, arg2);
|
|
return (total);
|
|
case XPATH_OP_EQUAL:
|
|
--
|
|
2.18.0
|
|
|