90 lines
2.7 KiB
Diff
90 lines
2.7 KiB
Diff
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Copied from Debian.
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Description: fix multiple integer overflows in the XML_GetBuffer function
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Multiple integer overflows in the XML_GetBuffer function in Expat through
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2.1.0, as used in Google Chrome before 44.0.2403.89 and other products,
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allow remote attackers to cause a denial of service (heap-based buffer
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overflow) or possibly have unspecified other impact via crafted XML data,
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a related issue to CVE-2015-2716.
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Origin: Mozilla, https://hg.mozilla.org/releases/mozilla-esr31/rev/2f3e78643f5c
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Author: Eric Rahm <erahm@mozilla.com>
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Forwarded: not-needed
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Last-Update: 2015-07-24
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diff --git a/lib/xmlparse.c b/lib/xmlparse.c
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--- a/lib/xmlparse.c
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+++ b/lib/xmlparse.c
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@@ -1673,29 +1673,40 @@ XML_ParseBuffer(XML_Parser parser, int l
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XmlUpdatePosition(encoding, positionPtr, bufferPtr, &position);
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positionPtr = bufferPtr;
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return result;
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}
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void * XMLCALL
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XML_GetBuffer(XML_Parser parser, int len)
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{
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+/* BEGIN MOZILLA CHANGE (sanity check len) */
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+ if (len < 0) {
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+ errorCode = XML_ERROR_NO_MEMORY;
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+ return NULL;
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+ }
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+/* END MOZILLA CHANGE */
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switch (ps_parsing) {
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case XML_SUSPENDED:
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errorCode = XML_ERROR_SUSPENDED;
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return NULL;
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case XML_FINISHED:
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errorCode = XML_ERROR_FINISHED;
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return NULL;
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default: ;
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}
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if (len > bufferLim - bufferEnd) {
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- /* FIXME avoid integer overflow */
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int neededSize = len + (int)(bufferEnd - bufferPtr);
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+/* BEGIN MOZILLA CHANGE (sanity check neededSize) */
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+ if (neededSize < 0) {
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+ errorCode = XML_ERROR_NO_MEMORY;
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+ return NULL;
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+ }
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+/* END MOZILLA CHANGE */
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#ifdef XML_CONTEXT_BYTES
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int keep = (int)(bufferPtr - buffer);
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if (keep > XML_CONTEXT_BYTES)
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keep = XML_CONTEXT_BYTES;
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neededSize += keep;
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#endif /* defined XML_CONTEXT_BYTES */
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if (neededSize <= bufferLim - buffer) {
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@@ -1714,17 +1725,25 @@ XML_GetBuffer(XML_Parser parser, int len
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}
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else {
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char *newBuf;
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int bufferSize = (int)(bufferLim - bufferPtr);
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if (bufferSize == 0)
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bufferSize = INIT_BUFFER_SIZE;
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do {
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bufferSize *= 2;
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- } while (bufferSize < neededSize);
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+/* BEGIN MOZILLA CHANGE (prevent infinite loop on overflow) */
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+ } while (bufferSize < neededSize && bufferSize > 0);
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+/* END MOZILLA CHANGE */
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+/* BEGIN MOZILLA CHANGE (sanity check bufferSize) */
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+ if (bufferSize <= 0) {
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+ errorCode = XML_ERROR_NO_MEMORY;
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+ return NULL;
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+ }
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+/* END MOZILLA CHANGE */
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newBuf = (char *)MALLOC(bufferSize);
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if (newBuf == 0) {
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errorCode = XML_ERROR_NO_MEMORY;
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return NULL;
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}
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bufferLim = newBuf + bufferSize;
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#ifdef XML_CONTEXT_BYTES
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if (bufferPtr) {
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