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author | Brian C. Young <bcyoung@google.com> | 2017-04-03 12:39:04 -0700 |
---|---|---|
committer | gitbuildkicker <android-build@google.com> | 2017-04-17 16:24:07 -0700 |
commit | 8ea80f29ea5fdf383ee3ae59ce35e55421a339f8 (patch) | |
tree | 4429dedea0c3e78570da6c646ed5b55e55e1771c | |
parent | ff20cd797822dba8569ee518c44e6864d6b4ebfa (diff) | |
download | android_external_libxml2-8ea80f29ea5fdf383ee3ae59ce35e55421a339f8.tar.gz android_external_libxml2-8ea80f29ea5fdf383ee3ae59ce35e55421a339f8.tar.bz2 android_external_libxml2-8ea80f29ea5fdf383ee3ae59ce35e55421a339f8.zip |
DO NOT MERGE: Disallow namespace nodes in XPointer ranges
Namespace nodes must be copied to avoid use-after-free errors.
But they don't necessarily have a physical representation in a
document, so simply disallow them in XPointer ranges.
Found with afl-fuzz.
Fixes CVE-2016-4658.
Bug: 36554207
Change-Id: Ie570c4a53ae8ca82ed4ca19701ab7d8ba9b0468f
(cherry picked from commit cde4b40a9c17aec816c6b2577250fff9354a6f3c)
-rw-r--r-- | xpointer.c | 149 |
1 files changed, 56 insertions, 93 deletions
@@ -320,6 +320,45 @@ xmlXPtrRangesEqual(xmlXPathObjectPtr range1, xmlXPathObjectPtr range2) { } /** + * xmlXPtrNewRangeInternal: + * @start: the starting node + * @startindex: the start index + * @end: the ending point + * @endindex: the ending index + * + * Internal function to create a new xmlXPathObjectPtr of type range + * + * Returns the newly created object. + */ +static xmlXPathObjectPtr +xmlXPtrNewRangeInternal(xmlNodePtr start, int startindex, + xmlNodePtr end, int endindex) { + xmlXPathObjectPtr ret; + + /* + * Namespace nodes must be copied (see xmlXPathNodeSetDupNs). + * Disallow them for now. + */ + if ((start != NULL) && (start->type == XML_NAMESPACE_DECL)) + return(NULL); + if ((end != NULL) && (end->type == XML_NAMESPACE_DECL)) + return(NULL); + + ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); + if (ret == NULL) { + xmlXPtrErrMemory("allocating range"); + return(NULL); + } + memset(ret, 0, sizeof(xmlXPathObject)); + ret->type = XPATH_RANGE; + ret->user = start; + ret->index = startindex; + ret->user2 = end; + ret->index2 = endindex; + return(ret); +} + +/** * xmlXPtrNewRange: * @start: the starting node * @startindex: the start index @@ -344,17 +383,7 @@ xmlXPtrNewRange(xmlNodePtr start, int startindex, if (endindex < 0) return(NULL); - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start; - ret->index = startindex; - ret->user2 = end; - ret->index2 = endindex; + ret = xmlXPtrNewRangeInternal(start, startindex, end, endindex); xmlXPtrRangeCheckOrder(ret); return(ret); } @@ -381,17 +410,8 @@ xmlXPtrNewRangePoints(xmlXPathObjectPtr start, xmlXPathObjectPtr end) { if (end->type != XPATH_POINT) return(NULL); - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start->user; - ret->index = start->index; - ret->user2 = end->user; - ret->index2 = end->index; + ret = xmlXPtrNewRangeInternal(start->user, start->index, end->user, + end->index); xmlXPtrRangeCheckOrder(ret); return(ret); } @@ -416,17 +436,7 @@ xmlXPtrNewRangePointNode(xmlXPathObjectPtr start, xmlNodePtr end) { if (start->type != XPATH_POINT) return(NULL); - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start->user; - ret->index = start->index; - ret->user2 = end; - ret->index2 = -1; + ret = xmlXPtrNewRangeInternal(start->user, start->index, end, -1); xmlXPtrRangeCheckOrder(ret); return(ret); } @@ -453,17 +463,7 @@ xmlXPtrNewRangeNodePoint(xmlNodePtr start, xmlXPathObjectPtr end) { if (end->type != XPATH_POINT) return(NULL); - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start; - ret->index = -1; - ret->user2 = end->user; - ret->index2 = end->index; + ret = xmlXPtrNewRangeInternal(start, -1, end->user, end->index); xmlXPtrRangeCheckOrder(ret); return(ret); } @@ -486,17 +486,7 @@ xmlXPtrNewRangeNodes(xmlNodePtr start, xmlNodePtr end) { if (end == NULL) return(NULL); - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start; - ret->index = -1; - ret->user2 = end; - ret->index2 = -1; + ret = xmlXPtrNewRangeInternal(start, -1, end, -1); xmlXPtrRangeCheckOrder(ret); return(ret); } @@ -516,17 +506,7 @@ xmlXPtrNewCollapsedRange(xmlNodePtr start) { if (start == NULL) return(NULL); - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start; - ret->index = -1; - ret->user2 = NULL; - ret->index2 = -1; + ret = xmlXPtrNewRangeInternal(start, -1, NULL, -1); return(ret); } @@ -541,6 +521,8 @@ xmlXPtrNewCollapsedRange(xmlNodePtr start) { */ xmlXPathObjectPtr xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) { + xmlNodePtr endNode; + int endIndex; xmlXPathObjectPtr ret; if (start == NULL) @@ -549,7 +531,12 @@ xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) { return(NULL); switch (end->type) { case XPATH_POINT: + endNode = end->user; + endIndex = end->index; + break; case XPATH_RANGE: + endNode = end->user2; + endIndex = end->index2; break; case XPATH_NODESET: /* @@ -557,39 +544,15 @@ xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) { */ if (end->nodesetval->nodeNr <= 0) return(NULL); + endNode = end->nodesetval->nodeTab[end->nodesetval->nodeNr - 1]; + endIndex = -1; break; default: /* TODO */ return(NULL); } - ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject)); - if (ret == NULL) { - xmlXPtrErrMemory("allocating range"); - return(NULL); - } - memset(ret, 0 , (size_t) sizeof(xmlXPathObject)); - ret->type = XPATH_RANGE; - ret->user = start; - ret->index = -1; - switch (end->type) { - case XPATH_POINT: - ret->user2 = end->user; - ret->index2 = end->index; - break; - case XPATH_RANGE: - ret->user2 = end->user2; - ret->index2 = end->index2; - break; - case XPATH_NODESET: { - ret->user2 = end->nodesetval->nodeTab[end->nodesetval->nodeNr - 1]; - ret->index2 = -1; - break; - } - default: - STRANGE - return(NULL); - } + ret = xmlXPtrNewRangeInternal(start, -1, endNode, endIndex); xmlXPtrRangeCheckOrder(ret); return(ret); } |