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expat/expat-2.5.0-CVE-2023-52425.patch

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Fix parsing of large tokens Reject direct parameter entity recursion Resolves: RHEL-29699 Resolves: RHEL-29696
2024-02-13 15:37:45 +00:00
commit 678a2f7efcaaa977886e055613f2332615aef82c
Author: Tomas Korbar <tkorbar@redhat.com>
Date: Tue Feb 13 13:52:28 2024 +0100
Fix CVE-2023-52425
diff --git a/expat/Makefile.am b/expat/Makefile.am
index 37ae373..cd0117f 100644
--- a/expat/Makefile.am
+++ b/expat/Makefile.am
@@ -131,6 +131,11 @@ buildlib:
run-benchmark:
$(MAKE) -C tests/benchmark
./run.sh tests/benchmark/benchmark@EXEEXT@ -n $(top_srcdir)/../testdata/largefiles/recset.xml 65535 3
+ ./run.sh tests/benchmark/benchmark@EXEEXT@ -n $(top_srcdir)/../testdata/largefiles/aaaaaa_attr.xml 4096 3
+ ./run.sh tests/benchmark/benchmark@EXEEXT@ -n $(top_srcdir)/../testdata/largefiles/aaaaaa_cdata.xml 4096 3
+ ./run.sh tests/benchmark/benchmark@EXEEXT@ -n $(top_srcdir)/../testdata/largefiles/aaaaaa_comment.xml 4096 3
+ ./run.sh tests/benchmark/benchmark@EXEEXT@ -n $(top_srcdir)/../testdata/largefiles/aaaaaa_tag.xml 4096 3
+ ./run.sh tests/benchmark/benchmark@EXEEXT@ -n $(top_srcdir)/../testdata/largefiles/aaaaaa_text.xml 4096 3
.PHONY: download-xmlts-zip
download-xmlts-zip:
diff --git a/expat/doc/reference.html b/expat/doc/reference.html
index 8b0d47d..a10f3cb 100644
--- a/expat/doc/reference.html
+++ b/expat/doc/reference.html
@@ -151,10 +151,11 @@ interface.</p>
</ul>
</li>
<li>
- <a href="#billion-laughs">Billion Laughs Attack Protection</a>
+ <a href="#attack-protection">Attack Protection</a>
<ul>
<li><a href="#XML_SetBillionLaughsAttackProtectionMaximumAmplification">XML_SetBillionLaughsAttackProtectionMaximumAmplification</a></li>
<li><a href="#XML_SetBillionLaughsAttackProtectionActivationThreshold">XML_SetBillionLaughsAttackProtectionActivationThreshold</a></li>
+ <li><a href="#XML_SetReparseDeferralEnabled">XML_SetReparseDeferralEnabled</a></li>
</ul>
</li>
<li><a href="#miscellaneous">Miscellaneous Functions</a>
@@ -2096,11 +2097,7 @@ parse position may be before the beginning of the buffer.</p>
return NULL.</p>
</div>
-<h3><a name="billion-laughs">Billion Laughs Attack Protection</a></h3>
-
-<p>The functions in this section configure the built-in
- protection against various forms of
- <a href="https://en.wikipedia.org/wiki/Billion_laughs_attack">billion laughs attacks</a>.</p>
+<h3><a name="attack-protection">Attack Protection</a><a name="billion-laughs"></a></h3>
<h4 id="XML_SetBillionLaughsAttackProtectionMaximumAmplification">XML_SetBillionLaughsAttackProtectionMaximumAmplification</h4>
<pre class="fcndec">
@@ -2188,6 +2185,27 @@ XML_SetBillionLaughsAttackProtectionActivationThreshold(XML_Parser p,
</p>
</div>
+<h4 id="XML_SetReparseDeferralEnabled">XML_SetReparseDeferralEnabled</h4>
+<pre class="fcndec">
+/* Added in Expat 2.6.0. */
+XML_Bool XMLCALL
+XML_SetReparseDeferralEnabled(XML_Parser parser, XML_Bool enabled);
+</pre>
+<div class="fcndef">
+ <p>
+ Large tokens may require many parse calls before enough data is available for Expat to parse it in full.
+ If Expat retried parsing the token on every parse call, parsing could take quadratic time.
+ To avoid this, Expat only retries once a significant amount of new data is available.
+ This function allows disabling this behavior.
+ </p>
+ <p>
+ The <code>enabled</code> argument should be <code>XML_TRUE</code> or <code>XML_FALSE</code>.
+ </p>
+ <p>
+ Returns <code>XML_TRUE</code> on success, and <code>XML_FALSE</code> on error.
+ </p>
+</div>
+
<h3><a name="miscellaneous">Miscellaneous functions</a></h3>
<p>The functions in this section either obtain state information from
diff --git a/expat/doc/xmlwf.xml b/expat/doc/xmlwf.xml
index 9603abf..3d35393 100644
--- a/expat/doc/xmlwf.xml
+++ b/expat/doc/xmlwf.xml
@@ -313,6 +313,16 @@ supports both.
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>-q</option></term>
+ <listitem>
+ <para>
+ Disable reparse deferral, and allow quadratic parse runtime
+ on large tokens (default: reparse deferral enabled).
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-r</option></term>
<listitem>
diff --git a/expat/lib/expat.h b/expat/lib/expat.h
index 1c83563..842dd70 100644
--- a/expat/lib/expat.h
+++ b/expat/lib/expat.h
@@ -16,6 +16,7 @@
Copyright (c) 2016 Thomas Beutlich <tc@tbeu.de>
Copyright (c) 2017 Rhodri James <rhodri@wildebeest.org.uk>
Copyright (c) 2022 Thijs Schreijer <thijs@thijsschreijer.nl>
+ Copyright (c) 2023 Sony Corporation / Snild Dolkow <snild@sony.com>
Licensed under the MIT license:
Permission is hereby granted, free of charge, to any person obtaining
@@ -1050,6 +1051,10 @@ XML_SetBillionLaughsAttackProtectionActivationThreshold(
XML_Parser parser, unsigned long long activationThresholdBytes);
#endif
+/* Added in Expat 2.6.0. */
+XMLPARSEAPI(XML_Bool)
+XML_SetReparseDeferralEnabled(XML_Parser parser, XML_Bool enabled);
+
/* Expat follows the semantic versioning convention.
See http://semver.org.
*/
diff --git a/expat/lib/internal.h b/expat/lib/internal.h
index e09f533..e2709c8 100644
--- a/expat/lib/internal.h
+++ b/expat/lib/internal.h
@@ -31,6 +31,7 @@
Copyright (c) 2016-2022 Sebastian Pipping <sebastian@pipping.org>
Copyright (c) 2018 Yury Gribov <tetra2005@gmail.com>
Copyright (c) 2019 David Loffredo <loffredo@steptools.com>
+ Copyright (c) 2023 Sony Corporation / Snild Dolkow <snild@sony.com>
Licensed under the MIT license:
Permission is hereby granted, free of charge, to any person obtaining
@@ -160,6 +161,9 @@ unsigned long long testingAccountingGetCountBytesIndirect(XML_Parser parser);
const char *unsignedCharToPrintable(unsigned char c);
#endif
+extern XML_Bool g_reparseDeferralEnabledDefault; // written ONLY in runtests.c
+extern unsigned int g_parseAttempts; // used for testing only
+
#ifdef __cplusplus
}
#endif
diff --git a/expat/lib/libexpat.def.cmake b/expat/lib/libexpat.def.cmake
index cf434a2..3ff4d55 100644
--- a/expat/lib/libexpat.def.cmake
+++ b/expat/lib/libexpat.def.cmake
@@ -77,3 +77,4 @@ EXPORTS
; added with version 2.4.0
@_EXPAT_COMMENT_DTD@ XML_SetBillionLaughsAttackProtectionActivationThreshold @69
@_EXPAT_COMMENT_DTD@ XML_SetBillionLaughsAttackProtectionMaximumAmplification @70
+XML_SetReparseDeferralEnabled @71
diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
index b6c2eca..2ae64e9 100644
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -73,6 +73,7 @@
# endif
#endif
+#include <stdbool.h>
#include <stddef.h>
#include <string.h> /* memset(), memcpy() */
#include <assert.h>
@@ -196,6 +197,8 @@ typedef char ICHAR;
/* Do safe (NULL-aware) pointer arithmetic */
#define EXPAT_SAFE_PTR_DIFF(p, q) (((p) && (q)) ? ((p) - (q)) : 0)
+#define EXPAT_MIN(a, b) (((a) < (b)) ? (a) : (b))
+
#include "internal.h"
#include "xmltok.h"
#include "xmlrole.h"
@@ -602,6 +605,9 @@ static unsigned long getDebugLevel(const char *variableName,
? 0 \
: ((*((pool)->ptr)++ = c), 1))
+XML_Bool g_reparseDeferralEnabledDefault = XML_TRUE; // write ONLY in runtests.c
+unsigned int g_parseAttempts = 0; // used for testing only
+
struct XML_ParserStruct {
/* The first member must be m_userData so that the XML_GetUserData
macro works. */
@@ -617,6 +623,9 @@ struct XML_ParserStruct {
const char *m_bufferLim;
XML_Index m_parseEndByteIndex;
const char *m_parseEndPtr;
+ size_t m_partialTokenBytesBefore; /* used in heuristic to avoid O(n^2) */
+ XML_Bool m_reparseDeferralEnabled;
+ int m_lastBufferRequestSize;
XML_Char *m_dataBuf;
XML_Char *m_dataBufEnd;
XML_StartElementHandler m_startElementHandler;
@@ -948,6 +957,47 @@ get_hash_secret_salt(XML_Parser parser) {
return parser->m_hash_secret_salt;
}
+static enum XML_Error
+callProcessor(XML_Parser parser, const char *start, const char *end,
+ const char **endPtr) {
+ const size_t have_now = EXPAT_SAFE_PTR_DIFF(end, start);
+
+ if (parser->m_reparseDeferralEnabled
+ && ! parser->m_parsingStatus.finalBuffer) {
+ // Heuristic: don't try to parse a partial token again until the amount of
+ // available data has increased significantly.
+ const size_t had_before = parser->m_partialTokenBytesBefore;
+ // ...but *do* try anyway if we're close to causing a reallocation.
+ size_t available_buffer
+ = EXPAT_SAFE_PTR_DIFF(parser->m_bufferPtr, parser->m_buffer);
+#if XML_CONTEXT_BYTES > 0
+ available_buffer -= EXPAT_MIN(available_buffer, XML_CONTEXT_BYTES);
+#endif
+ available_buffer
+ += EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_bufferEnd);
+ // m_lastBufferRequestSize is never assigned a value < 0, so the cast is ok
+ const bool enough
+ = (have_now >= 2 * had_before)
+ || ((size_t)parser->m_lastBufferRequestSize > available_buffer);
+
+ if (! enough) {
+ *endPtr = start; // callers may expect this to be set
+ return XML_ERROR_NONE;
+ }
+ }
+ g_parseAttempts += 1;
+ const enum XML_Error ret = parser->m_processor(parser, start, end, endPtr);
+ if (ret == XML_ERROR_NONE) {
+ // if we consumed nothing, remember what we had on this parse attempt.
+ if (*endPtr == start) {
+ parser->m_partialTokenBytesBefore = have_now;
+ } else {
+ parser->m_partialTokenBytesBefore = 0;
+ }
+ }
+ return ret;
+}
+
static XML_Bool /* only valid for root parser */
startParsing(XML_Parser parser) {
/* hash functions must be initialized before setContext() is called */
@@ -1129,6 +1179,9 @@ parserInit(XML_Parser parser, const XML_Char *encodingName) {
parser->m_bufferEnd = parser->m_buffer;
parser->m_parseEndByteIndex = 0;
parser->m_parseEndPtr = NULL;
+ parser->m_partialTokenBytesBefore = 0;
+ parser->m_reparseDeferralEnabled = g_reparseDeferralEnabledDefault;
+ parser->m_lastBufferRequestSize = 0;
parser->m_declElementType = NULL;
parser->m_declAttributeId = NULL;
parser->m_declEntity = NULL;
@@ -1298,6 +1351,7 @@ XML_ExternalEntityParserCreate(XML_Parser oldParser, const XML_Char *context,
to worry which hash secrets each table has.
*/
unsigned long oldhash_secret_salt;
+ XML_Bool oldReparseDeferralEnabled;
/* Validate the oldParser parameter before we pull everything out of it */
if (oldParser == NULL)
@@ -1342,6 +1396,7 @@ XML_ExternalEntityParserCreate(XML_Parser oldParser, const XML_Char *context,
to worry which hash secrets each table has.
*/
oldhash_secret_salt = parser->m_hash_secret_salt;
+ oldReparseDeferralEnabled = parser->m_reparseDeferralEnabled;
#ifdef XML_DTD
if (! context)
@@ -1394,6 +1449,7 @@ XML_ExternalEntityParserCreate(XML_Parser oldParser, const XML_Char *context,
parser->m_defaultExpandInternalEntities = oldDefaultExpandInternalEntities;
parser->m_ns_triplets = oldns_triplets;
parser->m_hash_secret_salt = oldhash_secret_salt;
+ parser->m_reparseDeferralEnabled = oldReparseDeferralEnabled;
parser->m_parentParser = oldParser;
#ifdef XML_DTD
parser->m_paramEntityParsing = oldParamEntityParsing;
@@ -1848,55 +1904,8 @@ XML_Parse(XML_Parser parser, const char *s, int len, int isFinal) {
parser->m_parsingStatus.parsing = XML_PARSING;
}
- if (len == 0) {
- parser->m_parsingStatus.finalBuffer = (XML_Bool)isFinal;
- if (! isFinal)
- return XML_STATUS_OK;
- parser->m_positionPtr = parser->m_bufferPtr;
- parser->m_parseEndPtr = parser->m_bufferEnd;
-
- /* If data are left over from last buffer, and we now know that these
- data are the final chunk of input, then we have to check them again
- to detect errors based on that fact.
- */
- parser->m_errorCode
- = parser->m_processor(parser, parser->m_bufferPtr,
- parser->m_parseEndPtr, &parser->m_bufferPtr);
-
- if (parser->m_errorCode == XML_ERROR_NONE) {
- switch (parser->m_parsingStatus.parsing) {
- case XML_SUSPENDED:
- /* It is hard to be certain, but it seems that this case
- * cannot occur. This code is cleaning up a previous parse
- * with no new data (since len == 0). Changing the parsing
- * state requires getting to execute a handler function, and
- * there doesn't seem to be an opportunity for that while in
- * this circumstance.
- *
- * Given the uncertainty, we retain the code but exclude it
- * from coverage tests.
- *
- * LCOV_EXCL_START
- */
- XmlUpdatePosition(parser->m_encoding, parser->m_positionPtr,
- parser->m_bufferPtr, &parser->m_position);
- parser->m_positionPtr = parser->m_bufferPtr;
- return XML_STATUS_SUSPENDED;
- /* LCOV_EXCL_STOP */
- case XML_INITIALIZED:
- case XML_PARSING:
- parser->m_parsingStatus.parsing = XML_FINISHED;
- /* fall through */
- default:
- return XML_STATUS_OK;
- }
- }
- parser->m_eventEndPtr = parser->m_eventPtr;
- parser->m_processor = errorProcessor;
- return XML_STATUS_ERROR;
- }
#ifndef XML_CONTEXT_BYTES
- else if (parser->m_bufferPtr == parser->m_bufferEnd) {
+ if (parser->m_bufferPtr == parser->m_bufferEnd) {
const char *end;
int nLeftOver;
enum XML_Status result;
@@ -1907,12 +1916,15 @@ XML_Parse(XML_Parser parser, const char *s, int len, int isFinal) {
parser->m_processor = errorProcessor;
return XML_STATUS_ERROR;
}
+ // though this isn't a buffer request, we assume that `len` is the app's
+ // preferred buffer fill size, and therefore save it here.
+ parser->m_lastBufferRequestSize = len;
parser->m_parseEndByteIndex += len;
parser->m_positionPtr = s;
parser->m_parsingStatus.finalBuffer = (XML_Bool)isFinal;
parser->m_errorCode
- = parser->m_processor(parser, s, parser->m_parseEndPtr = s + len, &end);
+ = callProcessor(parser, s, parser->m_parseEndPtr = s + len, &end);
if (parser->m_errorCode != XML_ERROR_NONE) {
parser->m_eventEndPtr = parser->m_eventPtr;
@@ -1939,23 +1951,25 @@ XML_Parse(XML_Parser parser, const char *s, int len, int isFinal) {
&parser->m_position);
nLeftOver = s + len - end;
if (nLeftOver) {
- if (parser->m_buffer == NULL
- || nLeftOver > parser->m_bufferLim - parser->m_buffer) {
- /* avoid _signed_ integer overflow */
- char *temp = NULL;
- const int bytesToAllocate = (int)((unsigned)len * 2U);
- if (bytesToAllocate > 0) {
- temp = (char *)REALLOC(parser, parser->m_buffer, bytesToAllocate);
- }
- if (temp == NULL) {
- parser->m_errorCode = XML_ERROR_NO_MEMORY;
- parser->m_eventPtr = parser->m_eventEndPtr = NULL;
- parser->m_processor = errorProcessor;
- return XML_STATUS_ERROR;
- }
- parser->m_buffer = temp;
- parser->m_bufferLim = parser->m_buffer + bytesToAllocate;
+ // Back up and restore the parsing status to avoid XML_ERROR_SUSPENDED
+ // (and XML_ERROR_FINISHED) from XML_GetBuffer.
+ const enum XML_Parsing originalStatus = parser->m_parsingStatus.parsing;
+ parser->m_parsingStatus.parsing = XML_PARSING;
+ void *const temp = XML_GetBuffer(parser, nLeftOver);
+ parser->m_parsingStatus.parsing = originalStatus;
+ // GetBuffer may have overwritten this, but we want to remember what the
+ // app requested, not how many bytes were left over after parsing.
+ parser->m_lastBufferRequestSize = len;
+ if (temp == NULL) {
+ // NOTE: parser->m_errorCode has already been set by XML_GetBuffer().
+ parser->m_eventPtr = parser->m_eventEndPtr = NULL;
+ parser->m_processor = errorProcessor;
+ return XML_STATUS_ERROR;
}
+ // Since we know that the buffer was empty and XML_CONTEXT_BYTES is 0, we
+ // don't have any data to preserve, and can copy straight into the start
+ // of the buffer rather than the GetBuffer return pointer (which may be
+ // pointing further into the allocated buffer).
memcpy(parser->m_buffer, end, nLeftOver);
}
parser->m_bufferPtr = parser->m_buffer;
@@ -1967,15 +1981,14 @@ XML_Parse(XML_Parser parser, const char *s, int len, int isFinal) {
return result;
}
#endif /* not defined XML_CONTEXT_BYTES */
- else {
- void *buff = XML_GetBuffer(parser, len);
- if (buff == NULL)
- return XML_STATUS_ERROR;
- else {
- memcpy(buff, s, len);
- return XML_ParseBuffer(parser, len, isFinal);
- }
+ void *buff = XML_GetBuffer(parser, len);
+ if (buff == NULL)
+ return XML_STATUS_ERROR;
+ if (len > 0) {
+ assert(s != NULL); // make sure s==NULL && len!=0 was rejected above
+ memcpy(buff, s, len);
}
+ return XML_ParseBuffer(parser, len, isFinal);
}
enum XML_Status XMLCALL
@@ -2015,8 +2028,8 @@ XML_ParseBuffer(XML_Parser parser, int len, int isFinal) {
parser->m_parseEndByteIndex += len;
parser->m_parsingStatus.finalBuffer = (XML_Bool)isFinal;
- parser->m_errorCode = parser->m_processor(
- parser, start, parser->m_parseEndPtr, &parser->m_bufferPtr);
+ parser->m_errorCode = callProcessor(parser, start, parser->m_parseEndPtr,
+ &parser->m_bufferPtr);
if (parser->m_errorCode != XML_ERROR_NONE) {
parser->m_eventEndPtr = parser->m_eventPtr;
@@ -2061,10 +2074,14 @@ XML_GetBuffer(XML_Parser parser, int len) {
default:;
}
- if (len > EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_bufferEnd)) {
-#ifdef XML_CONTEXT_BYTES
+ // whether or not the request succeeds, `len` seems to be the app's preferred
+ // buffer fill size; remember it.
+ parser->m_lastBufferRequestSize = len;
+ if (len > EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_bufferEnd)
+ || parser->m_buffer == NULL) {
+#if XML_CONTEXT_BYTES > 0
int keep;
-#endif /* defined XML_CONTEXT_BYTES */
+#endif /* XML_CONTEXT_BYTES > 0 */
/* Do not invoke signed arithmetic overflow: */
int neededSize = (int)((unsigned)len
+ (unsigned)EXPAT_SAFE_PTR_DIFF(
@@ -2073,7 +2090,7 @@ XML_GetBuffer(XML_Parser parser, int len) {
parser->m_errorCode = XML_ERROR_NO_MEMORY;
return NULL;
}
-#ifdef XML_CONTEXT_BYTES
+#if XML_CONTEXT_BYTES > 0
keep = (int)EXPAT_SAFE_PTR_DIFF(parser->m_bufferPtr, parser->m_buffer);
if (keep > XML_CONTEXT_BYTES)
keep = XML_CONTEXT_BYTES;
@@ -2083,10 +2100,11 @@ XML_GetBuffer(XML_Parser parser, int len) {
return NULL;
}
neededSize += keep;
-#endif /* defined XML_CONTEXT_BYTES */
- if (neededSize
- <= EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_buffer)) {
-#ifdef XML_CONTEXT_BYTES
+#endif /* XML_CONTEXT_BYTES > 0 */
+ if (parser->m_buffer && parser->m_bufferPtr
+ && neededSize
+ <= EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_buffer)) {
+#if XML_CONTEXT_BYTES > 0
if (keep < EXPAT_SAFE_PTR_DIFF(parser->m_bufferPtr, parser->m_buffer)) {
int offset
= (int)EXPAT_SAFE_PTR_DIFF(parser->m_bufferPtr, parser->m_buffer)
@@ -2099,19 +2117,17 @@ XML_GetBuffer(XML_Parser parser, int len) {
parser->m_bufferPtr -= offset;
}
#else
- if (parser->m_buffer && parser->m_bufferPtr) {
- memmove(parser->m_buffer, parser->m_bufferPtr,
- EXPAT_SAFE_PTR_DIFF(parser->m_bufferEnd, parser->m_bufferPtr));
- parser->m_bufferEnd
- = parser->m_buffer
- + EXPAT_SAFE_PTR_DIFF(parser->m_bufferEnd, parser->m_bufferPtr);
- parser->m_bufferPtr = parser->m_buffer;
- }
-#endif /* not defined XML_CONTEXT_BYTES */
+ memmove(parser->m_buffer, parser->m_bufferPtr,
+ EXPAT_SAFE_PTR_DIFF(parser->m_bufferEnd, parser->m_bufferPtr));
+ parser->m_bufferEnd
+ = parser->m_buffer
+ + EXPAT_SAFE_PTR_DIFF(parser->m_bufferEnd, parser->m_bufferPtr);
+ parser->m_bufferPtr = parser->m_buffer;
+#endif /* XML_CONTEXT_BYTES > 0 */
} else {
char *newBuf;
int bufferSize
- = (int)EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_bufferPtr);
+ = (int)EXPAT_SAFE_PTR_DIFF(parser->m_bufferLim, parser->m_buffer);
if (bufferSize == 0)
bufferSize = INIT_BUFFER_SIZE;
do {
@@ -2128,7 +2144,7 @@ XML_GetBuffer(XML_Parser parser, int len) {
return NULL;
}
parser->m_bufferLim = newBuf + bufferSize;
-#ifdef XML_CONTEXT_BYTES
+#if XML_CONTEXT_BYTES > 0
if (parser->m_bufferPtr) {
memcpy(newBuf, &parser->m_bufferPtr[-keep],
EXPAT_SAFE_PTR_DIFF(parser->m_bufferEnd, parser->m_bufferPtr)
@@ -2158,7 +2174,7 @@ XML_GetBuffer(XML_Parser parser, int len) {
parser->m_bufferEnd = newBuf;
}
parser->m_bufferPtr = parser->m_buffer = newBuf;
-#endif /* not defined XML_CONTEXT_BYTES */
+#endif /* XML_CONTEXT_BYTES > 0 */
}
parser->m_eventPtr = parser->m_eventEndPtr = NULL;
parser->m_positionPtr = NULL;
@@ -2208,7 +2224,7 @@ XML_ResumeParser(XML_Parser parser) {
}
parser->m_parsingStatus.parsing = XML_PARSING;
- parser->m_errorCode = parser->m_processor(
+ parser->m_errorCode = callProcessor(
parser, parser->m_bufferPtr, parser->m_parseEndPtr, &parser->m_bufferPtr);
if (parser->m_errorCode != XML_ERROR_NONE) {
@@ -2561,6 +2577,15 @@ XML_SetBillionLaughsAttackProtectionActivationThreshold(
}
#endif /* XML_DTD */
+XML_Bool XMLCALL
+XML_SetReparseDeferralEnabled(XML_Parser parser, XML_Bool enabled) {
+ if (parser != NULL && (enabled == XML_TRUE || enabled == XML_FALSE)) {
+ parser->m_reparseDeferralEnabled = enabled;
+ return XML_TRUE;
+ }
+ return XML_FALSE;
+}
+
/* Initially tag->rawName always points into the parse buffer;
for those TAG instances opened while the current parse buffer was
processed, and not yet closed, we need to store tag->rawName in a more
@@ -4482,15 +4507,15 @@ entityValueInitProcessor(XML_Parser parser, const char *s, const char *end,
parser->m_processor = entityValueProcessor;
return entityValueProcessor(parser, next, end, nextPtr);
}
- /* If we are at the end of the buffer, this would cause XmlPrologTok to
- return XML_TOK_NONE on the next call, which would then cause the
- function to exit with *nextPtr set to s - that is what we want for other
- tokens, but not for the BOM - we would rather like to skip it;
- then, when this routine is entered the next time, XmlPrologTok will
- return XML_TOK_INVALID, since the BOM is still in the buffer
+ /* XmlPrologTok has now set the encoding based on the BOM it found, and we
+ must move s and nextPtr forward to consume the BOM.
+
+ If we didn't, and got XML_TOK_NONE from the next XmlPrologTok call, we
+ would leave the BOM in the buffer and return. On the next call to this
+ function, our XmlPrologTok call would return XML_TOK_INVALID, since it
+ is not valid to have multiple BOMs.
*/
- else if (tok == XML_TOK_BOM && next == end
- && ! parser->m_parsingStatus.finalBuffer) {
+ else if (tok == XML_TOK_BOM) {
# ifdef XML_DTD
if (! accountingDiffTolerated(parser, tok, s, next, __LINE__,
XML_ACCOUNT_DIRECT)) {
@@ -4500,7 +4525,7 @@ entityValueInitProcessor(XML_Parser parser, const char *s, const char *end,
# endif
*nextPtr = next;
- return XML_ERROR_NONE;
+ s = next;
}
/* If we get this token, we have the start of what might be a
normal tag, but not a declaration (i.e. it doesn't begin with
diff --git a/expat/tests/minicheck.c b/expat/tests/minicheck.c
index 1c65748..f383380 100644
--- a/expat/tests/minicheck.c
+++ b/expat/tests/minicheck.c
@@ -208,6 +208,21 @@ srunner_run_all(SRunner *runner, int verbosity) {
}
}
+void
+_fail(const char *file, int line, const char *msg) {
+ /* Always print the error message so it isn't lost. In this case,
+ we have a failure, so there's no reason to be quiet about what
+ it is.
+ */
+ _check_current_filename = file;
+ _check_current_lineno = line;
+ if (msg != NULL) {
+ const int has_newline = (msg[strlen(msg) - 1] == '\n');
+ fprintf(stderr, "ERROR: %s%s", msg, has_newline ? "" : "\n");
+ }
+ longjmp(env, 1);
+}
+
void
_fail_unless(int condition, const char *file, int line, const char *msg) {
/* Always print the error message so it isn't lost. In this case,
diff --git a/expat/tests/minicheck.h b/expat/tests/minicheck.h
index cc1f835..032b54e 100644
--- a/expat/tests/minicheck.h
+++ b/expat/tests/minicheck.h
@@ -64,7 +64,14 @@ extern "C" {
} \
}
-#define fail(msg) _fail_unless(0, __FILE__, __LINE__, msg)
+
+# define fail(msg) _fail(__FILE__, __LINE__, msg)
+# define assert_true(cond) \
+ do { \
+ if (! (cond)) { \
+ _fail(__FILE__, __LINE__, "check failed: " #cond); \
+ } \
+ } while (0)
typedef void (*tcase_setup_function)(void);
typedef void (*tcase_teardown_function)(void);
@@ -103,6 +110,11 @@ void _check_set_test_info(char const *function, char const *filename,
* Prototypes for the actual implementation.
*/
+# if defined(__GNUC__)
+__attribute__((noreturn))
+# endif
+void
+_fail(const char *file, int line, const char *msg);
void _fail_unless(int condition, const char *file, int line, const char *msg);
Suite *suite_create(const char *name);
TCase *tcase_create(const char *name);
diff --git a/expat/tests/runtests.c b/expat/tests/runtests.c
index 915fa52..941f61d 100644
--- a/expat/tests/runtests.c
+++ b/expat/tests/runtests.c
@@ -54,6 +54,7 @@
#include <ctype.h>
#include <limits.h>
#include <stdint.h> /* intptr_t uint64_t */
+#include <time.h>
#if ! defined(__cplusplus)
# include <stdbool.h>
@@ -1071,7 +1072,7 @@ START_TEST(test_column_number_after_parse) {
const char *text = "<tag></tag>";
XML_Size colno;
- if (_XML_Parse_SINGLE_BYTES(g_parser, text, (int)strlen(text), XML_FALSE)
+ if (_XML_Parse_SINGLE_BYTES(g_parser, text, (int)strlen(text), XML_TRUE)
== XML_STATUS_ERROR)
xml_failure(g_parser);
colno = XML_GetCurrentColumnNumber(g_parser);
@@ -2582,7 +2583,7 @@ START_TEST(test_default_current) {
if (_XML_Parse_SINGLE_BYTES(g_parser, text, (int)strlen(text), XML_TRUE)
== XML_STATUS_ERROR)
xml_failure(g_parser);
- CharData_CheckXMLChars(&storage, XCS("DCDCDCDCDCDD"));
+ CharData_CheckXMLChars(&storage, XCS("DCDCDCDD"));
/* Again, without the defaulting */
XML_ParserReset(g_parser, NULL);
@@ -2593,7 +2594,7 @@ START_TEST(test_default_current) {
if (_XML_Parse_SINGLE_BYTES(g_parser, text, (int)strlen(text), XML_TRUE)
== XML_STATUS_ERROR)
xml_failure(g_parser);
- CharData_CheckXMLChars(&storage, XCS("DcccccD"));
+ CharData_CheckXMLChars(&storage, XCS("DcccD"));
/* Now with an internal entity to complicate matters */
XML_ParserReset(g_parser, NULL);
@@ -3946,6 +3947,19 @@ START_TEST(test_get_buffer_3_overflow) {
END_TEST
#endif // defined(XML_CONTEXT_BYTES)
+START_TEST(test_getbuffer_allocates_on_zero_len) {
+ for (int first_len = 1; first_len >= 0; first_len--) {
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(parser != NULL);
+ assert_true(XML_GetBuffer(parser, first_len) != NULL);
+ assert_true(XML_GetBuffer(parser, 0) != NULL);
+ if (XML_ParseBuffer(parser, 0, XML_FALSE) != XML_STATUS_OK)
+ xml_failure(parser);
+ XML_ParserFree(parser);
+ }
+}
+END_TEST
+
/* Test position information macros */
START_TEST(test_byte_info_at_end) {
const char *text = "<doc></doc>";
@@ -6205,6 +6219,12 @@ START_TEST(test_utf8_in_start_tags) {
char doc[1024];
size_t failCount = 0;
+ // we need all the bytes to be parsed, but we don't want the errors that can
+ // trigger on isFinal=XML_TRUE, so we skip the test if the heuristic is on.
+ if (g_reparseDeferralEnabledDefault) {
+ return;
+ }
+
for (; i < sizeof(cases) / sizeof(cases[0]); i++) {
size_t j = 0;
for (; j < sizeof(atNameStart) / sizeof(atNameStart[0]); j++) {
@@ -6830,6 +6850,613 @@ START_TEST(test_nested_entity_suspend) {
}
END_TEST
+/* Regression test for quadratic parsing on large tokens */
+START_TEST(test_big_tokens_take_linear_time) {
+ const char *const too_slow_failure_message
+ = "Compared to the baseline runtime of the first test, this test has a "
+ "slowdown of more than <max_slowdown>. "
+ "Please keep increasing the value by 1 until it reliably passes the "
+ "test on your hardware and open a bug sharing that number with us. "
+ "Thanks in advance!";
+ const struct {
+ const char *pre;
+ const char *post;
+ } text[] = {
+ {"<a>", "</a>"}, // assumed good, used as baseline
+ {"<b><![CDATA[ value: ", " ]]></b>"}, // CDATA, performed OK before patch
+ {"<c attr='", "'></c>"}, // big attribute, used to be O(N²)
+ {"<d><!-- ", " --></d>"}, // long comment, used to be O(N²)
+ {"<e><", "/></e>"}, // big elem name, used to be O(N²)
+ };
+ const int num_cases = sizeof(text) / sizeof(text[0]);
+ // For the test we need a <max_slowdown> value that is:
+ // (1) big enough that the test passes reliably (avoiding flaky tests), and
+ // (2) small enough that the test actually catches regressions.
+ const int max_slowdown = 15;
+ char aaaaaa[4096];
+ const int fillsize = (int)sizeof(aaaaaa);
+ const int fillcount = 100;
+
+ memset(aaaaaa, 'a', fillsize);
+
+ if (! g_reparseDeferralEnabledDefault) {
+ return; // heuristic is disabled; we would get O(n^2) and fail.
+ }
+#if defined(_WIN32)
+ if (CLOCKS_PER_SEC < 100000) {
+ // Skip this test if clock() doesn't have reasonably good resolution.
+ // This workaround is only applied to Windows targets, since XSI requires
+ // the value to be 1 000 000 (10x the condition here), and we want to be
+ // very sure that at least one platform in CI can catch regressions.
+ return;
+ }
+#endif
+
+ clock_t baseline = 0;
+ for (int i = 0; i < num_cases; ++i) {
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(parser != NULL);
+ enum XML_Status status;
+ const clock_t start = clock();
+
+ // parse the start text
+ status = _XML_Parse_SINGLE_BYTES(parser, text[i].pre,
+ (int)strlen(text[i].pre), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ // parse lots of 'a', failing the test early if it takes too long
+ for (int f = 0; f < fillcount; ++f) {
+ status = _XML_Parse_SINGLE_BYTES(parser, aaaaaa, fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ // i == 0 means we're still calculating the baseline value
+ if (i > 0) {
+ const clock_t now = clock();
+ const clock_t clocks_so_far = now - start;
+ const int slowdown = clocks_so_far / baseline;
+ if (slowdown >= max_slowdown) {
+ fprintf(
+ stderr,
+ "fill#%d: clocks_so_far=%d baseline=%d slowdown=%d max_slowdown=%d\n",
+ f, (int)clocks_so_far, (int)baseline, slowdown, max_slowdown);
+ fail(too_slow_failure_message);
+ }
+ }
+ }
+ // parse the end text
+ status = _XML_Parse_SINGLE_BYTES(parser, text[i].post,
+ (int)strlen(text[i].post), XML_TRUE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+
+ // how long did it take in total?
+ const clock_t end = clock();
+ const clock_t taken = end - start;
+ if (i == 0) {
+ assert_true(taken > 0); // just to make sure we don't div-by-0 later
+ baseline = taken;
+ }
+ const int slowdown = taken / baseline;
+ if (slowdown >= max_slowdown) {
+ fprintf(stderr, "taken=%d baseline=%d slowdown=%d max_slowdown=%d\n",
+ (int)taken, (int)baseline, slowdown, max_slowdown);
+ fail(too_slow_failure_message);
+ }
+
+ XML_ParserFree(parser);
+ }
+}
+END_TEST
+
+START_TEST(test_set_reparse_deferral) {
+ const char *const pre = "<d>";
+ const char *const start = "<x attr='";
+ const char *const end = "'></x>";
+ char eeeeee[100];
+ const int fillsize = (int)sizeof(eeeeee);
+ memset(eeeeee, 'e', fillsize);
+
+ for (int enabled = 0; enabled <= 1; enabled += 1) {
+
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(parser != NULL);
+ assert_true(XML_SetReparseDeferralEnabled(parser, enabled));
+ // pre-grow the buffer to avoid reparsing due to almost-fullness
+ assert_true(XML_GetBuffer(parser, fillsize * 10103) != NULL);
+
+ CharData storage;
+ CharData_Init(&storage);
+ XML_SetUserData(parser, &storage);
+ XML_SetStartElementHandler(parser, start_element_event_handler);
+
+ enum XML_Status status;
+ // parse the start text
+ status = XML_Parse(parser, pre, (int)strlen(pre), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ CharData_CheckXMLChars(&storage, XCS("d")); // first element should be done
+
+ // ..and the start of the token
+ status = XML_Parse(parser, start, (int)strlen(start), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ CharData_CheckXMLChars(&storage, XCS("d")); // still just the first one
+
+ // try to parse lots of 'e', but the token isn't finished
+ for (int c = 0; c < 100; ++c) {
+ status = XML_Parse(parser, eeeeee, fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ }
+ CharData_CheckXMLChars(&storage, XCS("d")); // *still* just the first one
+
+ // end the <x> token.
+ status = XML_Parse(parser, end, (int)strlen(end), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+
+ if (enabled) {
+ // In general, we may need to push more data to trigger a reparse attempt,
+ // but in this test, the data is constructed to always require it.
+ CharData_CheckXMLChars(&storage, XCS("d")); // or the test is incorrect
+ // 2x the token length should suffice; the +1 covers the start and end.
+ for (int c = 0; c < 101; ++c) {
+ status = XML_Parse(parser, eeeeee, fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ }
+ }
+ CharData_CheckXMLChars(&storage, XCS("dx")); // the <x> should be done
+
+ XML_ParserFree(parser);
+ }
+}
+END_TEST
+
+struct element_decl_data {
+ XML_Parser parser;
+ int count;
+};
+
+static void
+element_decl_counter(void *userData, const XML_Char *name, XML_Content *model) {
+ UNUSED_P(name);
+ struct element_decl_data *testdata = (struct element_decl_data *)userData;
+ testdata->count += 1;
+ XML_FreeContentModel(testdata->parser, model);
+}
+
+static int
+external_inherited_parser(XML_Parser p, const XML_Char *context,
+ const XML_Char *base, const XML_Char *systemId,
+ const XML_Char *publicId) {
+ UNUSED_P(base);
+ UNUSED_P(systemId);
+ UNUSED_P(publicId);
+ const char *const pre = "<!ELEMENT document ANY>\n";
+ const char *const start = "<!ELEMENT ";
+ const char *const end = " ANY>\n";
+ const char *const post = "<!ELEMENT xyz ANY>\n";
+ const int enabled = *(int *)XML_GetUserData(p);
+ char eeeeee[100];
+ char spaces[100];
+ const int fillsize = (int)sizeof(eeeeee);
+ assert_true(fillsize == (int)sizeof(spaces));
+ memset(eeeeee, 'e', fillsize);
+ memset(spaces, ' ', fillsize);
+
+ XML_Parser parser = XML_ExternalEntityParserCreate(p, context, NULL);
+ assert_true(parser != NULL);
+ // pre-grow the buffer to avoid reparsing due to almost-fullness
+ assert_true(XML_GetBuffer(parser, fillsize * 10103) != NULL);
+
+ struct element_decl_data testdata;
+ testdata.parser = parser;
+ testdata.count = 0;
+ XML_SetUserData(parser, &testdata);
+ XML_SetElementDeclHandler(parser, element_decl_counter);
+
+ enum XML_Status status;
+ // parse the initial text
+ status = XML_Parse(parser, pre, (int)strlen(pre), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ assert_true(testdata.count == 1); // first element should be done
+
+ // ..and the start of the big token
+ status = XML_Parse(parser, start, (int)strlen(start), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ assert_true(testdata.count == 1); // still just the first one
+
+ // try to parse lots of 'e', but the token isn't finished
+ for (int c = 0; c < 100; ++c) {
+ status = XML_Parse(parser, eeeeee, fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ }
+ assert_true(testdata.count == 1); // *still* just the first one
+
+ // end the big token.
+ status = XML_Parse(parser, end, (int)strlen(end), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+
+ if (enabled) {
+ // In general, we may need to push more data to trigger a reparse attempt,
+ // but in this test, the data is constructed to always require it.
+ assert_true(testdata.count == 1); // or the test is incorrect
+ // 2x the token length should suffice; the +1 covers the start and end.
+ for (int c = 0; c < 101; ++c) {
+ status = XML_Parse(parser, spaces, fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ }
+ }
+ assert_true(testdata.count == 2); // the big token should be done
+
+ // parse the final text
+ status = XML_Parse(parser, post, (int)strlen(post), XML_TRUE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ assert_true(testdata.count == 3); // after isFinal=XML_TRUE, all must be done
+
+ XML_ParserFree(parser);
+ return XML_STATUS_OK;
+}
+
+START_TEST(test_reparse_deferral_is_inherited) {
+ const char *const text
+ = "<!DOCTYPE document SYSTEM 'something.ext'><document/>";
+ for (int enabled = 0; enabled <= 1; ++enabled) {
+
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(parser != NULL);
+ XML_SetUserData(parser, (void *)&enabled);
+ XML_SetParamEntityParsing(parser, XML_PARAM_ENTITY_PARSING_ALWAYS);
+ // this handler creates a sub-parser and checks that its deferral behavior
+ // is what we expected, based on the value of `enabled` (in userdata).
+ XML_SetExternalEntityRefHandler(parser, external_inherited_parser);
+ assert_true(XML_SetReparseDeferralEnabled(parser, enabled));
+ if (XML_Parse(parser, text, (int)strlen(text), XML_TRUE) != XML_STATUS_OK)
+ xml_failure(parser);
+
+ XML_ParserFree(parser);
+ }
+}
+END_TEST
+
+START_TEST(test_set_reparse_deferral_on_null_parser) {
+ assert_true(XML_SetReparseDeferralEnabled(NULL, 0) == XML_FALSE);
+ assert_true(XML_SetReparseDeferralEnabled(NULL, 1) == XML_FALSE);
+ assert_true(XML_SetReparseDeferralEnabled(NULL, 10) == XML_FALSE);
+ assert_true(XML_SetReparseDeferralEnabled(NULL, 100) == XML_FALSE);
+ assert_true(XML_SetReparseDeferralEnabled(NULL, (XML_Bool)INT_MIN)
+ == XML_FALSE);
+ assert_true(XML_SetReparseDeferralEnabled(NULL, (XML_Bool)INT_MAX)
+ == XML_FALSE);
+}
+END_TEST
+
+START_TEST(test_set_reparse_deferral_on_the_fly) {
+ const char *const pre = "<d><x attr='";
+ const char *const end = "'></x>";
+ char iiiiii[100];
+ const int fillsize = (int)sizeof(iiiiii);
+ memset(iiiiii, 'i', fillsize);
+
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(parser != NULL);
+ assert_true(XML_SetReparseDeferralEnabled(parser, XML_TRUE));
+
+ CharData storage;
+ CharData_Init(&storage);
+ XML_SetUserData(parser, &storage);
+ XML_SetStartElementHandler(parser, start_element_event_handler);
+
+ enum XML_Status status;
+ // parse the start text
+ status = XML_Parse(parser, pre, (int)strlen(pre), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ CharData_CheckXMLChars(&storage, XCS("d")); // first element should be done
+
+ // try to parse some 'i', but the token isn't finished
+ status = XML_Parse(parser, iiiiii, fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ CharData_CheckXMLChars(&storage, XCS("d")); // *still* just the first one
+
+ // end the <x> token.
+ status = XML_Parse(parser, end, (int)strlen(end), XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ CharData_CheckXMLChars(&storage, XCS("d")); // not yet.
+
+ // now change the heuristic setting and add *no* data
+ assert_true(XML_SetReparseDeferralEnabled(parser, XML_FALSE));
+ // we avoid isFinal=XML_TRUE, because that would force-bypass the heuristic.
+ status = XML_Parse(parser, "", 0, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ CharData_CheckXMLChars(&storage, XCS("dx"));
+
+ XML_ParserFree(parser);
+}
+END_TEST
+
+START_TEST(test_set_bad_reparse_option) {
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 2));
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 3));
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 99));
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 127));
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 128));
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 129));
+ assert_true(XML_FALSE == XML_SetReparseDeferralEnabled(parser, 255));
+ assert_true(XML_TRUE == XML_SetReparseDeferralEnabled(parser, 0));
+ assert_true(XML_TRUE == XML_SetReparseDeferralEnabled(parser, 1));
+ XML_ParserFree(parser);
+}
+END_TEST
+
+static size_t g_totalAlloc = 0;
+static size_t g_biggestAlloc = 0;
+
+static void *
+counting_realloc(void *ptr, size_t size) {
+ g_totalAlloc += size;
+ if (size > g_biggestAlloc) {
+ g_biggestAlloc = size;
+ }
+ return realloc(ptr, size);
+}
+
+static void *
+counting_malloc(size_t size) {
+ return counting_realloc(NULL, size);
+}
+
+START_TEST(test_bypass_heuristic_when_close_to_bufsize) {
+ if (! g_reparseDeferralEnabledDefault) {
+ return; // this test is irrelevant when the deferral heuristic is disabled.
+ }
+
+ const int document_length = 65536;
+ char *const document = (char *)malloc(document_length);
+
+ const XML_Memory_Handling_Suite memfuncs = {
+ counting_malloc,
+ counting_realloc,
+ free,
+ };
+
+ const int leading_list[] = {0, 3, 61, 96, 400, 401, 4000, 4010, 4099, -1};
+ const int bigtoken_list[] = {3000, 4000, 4001, 4096, 4099, 5000, 20000, -1};
+ const int fillsize_list[] = {131, 256, 399, 400, 401, 1025, 4099, 4321, -1};
+
+ for (const int *leading = leading_list; *leading >= 0; leading++) {
+ for (const int *bigtoken = bigtoken_list; *bigtoken >= 0; bigtoken++) {
+ for (const int *fillsize = fillsize_list; *fillsize >= 0; fillsize++) {
+ // start by checking that the test looks reasonably valid
+ assert_true(*leading + *bigtoken <= document_length);
+
+ // put 'x' everywhere; some will be overwritten by elements.
+ memset(document, 'x', document_length);
+ // maybe add an initial tag
+ if (*leading) {
+ assert_true(*leading >= 3); // or the test case is invalid
+ memcpy(document, "<a>", 3);
+ }
+ // add the large token
+ document[*leading + 0] = '<';
+ document[*leading + 1] = 'b';
+ memset(&document[*leading + 2], ' ', *bigtoken - 2); // a spacy token
+ document[*leading + *bigtoken - 1] = '>';
+
+ // 1 for 'b', plus 1 or 0 depending on the presence of 'a'
+ const int expected_elem_total = 1 + (*leading ? 1 : 0);
+
+ XML_Parser parser = XML_ParserCreate_MM(NULL, &memfuncs, NULL);
+ assert_true(parser != NULL);
+
+ CharData storage;
+ CharData_Init(&storage);
+ XML_SetUserData(parser, &storage);
+ XML_SetStartElementHandler(parser, start_element_event_handler);
+
+ g_biggestAlloc = 0;
+ g_totalAlloc = 0;
+ int offset = 0;
+ // fill data until the big token is covered (but not necessarily parsed)
+ while (offset < *leading + *bigtoken) {
+ assert_true(offset + *fillsize <= document_length);
+ const enum XML_Status status
+ = XML_Parse(parser, &document[offset], *fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ offset += *fillsize;
+ }
+ // Now, check that we've had a buffer allocation that could fit the
+ // context bytes and our big token. In order to detect a special case,
+ // we need to know how many bytes of our big token were included in the
+ // first push that contained _any_ bytes of the big token:
+ const int bigtok_first_chunk_bytes = *fillsize - (*leading % *fillsize);
+ if (bigtok_first_chunk_bytes >= *bigtoken && XML_CONTEXT_BYTES == 0) {
+ // Special case: we aren't saving any context, and the whole big token
+ // was covered by a single fill, so Expat may have parsed directly
+ // from our input pointer, without allocating an internal buffer.
+ } else if (*leading < XML_CONTEXT_BYTES) {
+ assert_true(g_biggestAlloc >= *leading + (size_t)*bigtoken);
+ } else {
+ assert_true(g_biggestAlloc >= XML_CONTEXT_BYTES + (size_t)*bigtoken);
+ }
+ // fill data until the big token is actually parsed
+ while (storage.count < expected_elem_total) {
+ const size_t alloc_before = g_totalAlloc;
+ assert_true(offset + *fillsize <= document_length);
+ const enum XML_Status status
+ = XML_Parse(parser, &document[offset], *fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ offset += *fillsize;
+ // since all the bytes of the big token are already in the buffer,
+ // the bufsize ceiling should make us finish its parsing without any
+ // further buffer allocations. We assume that there will be no other
+ // large allocations in this test.
+ assert_true(g_totalAlloc - alloc_before < 4096);
+ }
+ // test-the-test: was our alloc even called?
+ assert_true(g_totalAlloc > 0);
+ // test-the-test: there shouldn't be any extra start elements
+ assert_true(storage.count == expected_elem_total);
+
+ XML_ParserFree(parser);
+ }
+ }
+ }
+ free(document);
+}
+END_TEST
+
+START_TEST(test_varying_buffer_fills) {
+ const int KiB = 1024;
+ const int MiB = 1024 * KiB;
+ const int document_length = 16 * MiB;
+ const int big = 7654321; // arbitrarily chosen between 4 and 8 MiB
+
+ char *const document = (char *)malloc(document_length);
+ assert_true(document != NULL);
+ memset(document, 'x', document_length);
+ document[0] = '<';
+ document[1] = 't';
+ memset(&document[2], ' ', big - 2); // a very spacy token
+ document[big - 1] = '>';
+
+ // Each testcase is a list of buffer fill sizes, terminated by a value < 0.
+ // When reparse deferral is enabled, the final (negated) value is the expected
+ // maximum number of bytes scanned in parse attempts.
+ const int testcases[][30] = {
+ {8 * MiB, -8 * MiB},
+ {4 * MiB, 4 * MiB, -12 * MiB}, // try at 4MB, then 8MB = 12 MB total
+ // zero-size fills shouldn't trigger the bypass
+ {4 * MiB, 0, 4 * MiB, -12 * MiB},
+ {4 * MiB, 0, 0, 4 * MiB, -12 * MiB},
+ {4 * MiB, 0, 1 * MiB, 0, 3 * MiB, -12 * MiB},
+ // try to hit the buffer ceiling only once (at the end)
+ {4 * MiB, 2 * MiB, 1 * MiB, 512 * KiB, 256 * KiB, 256 * KiB, -12 * MiB},
+ // try to hit the same buffer ceiling multiple times
+ {4 * MiB + 1, 2 * MiB, 1 * MiB, 512 * KiB, -25 * MiB},
+
+ // try to hit every ceiling, by always landing 1K shy of the buffer size
+ {1 * KiB, 2 * KiB, 4 * KiB, 8 * KiB, 16 * KiB, 32 * KiB, 64 * KiB,
+ 128 * KiB, 256 * KiB, 512 * KiB, 1 * MiB, 2 * MiB, 4 * MiB, -16 * MiB},
+
+ // try to avoid every ceiling, by always landing 1B past the buffer size
+ // the normal 2x heuristic threshold still forces parse attempts.
+ {2 * KiB + 1, // will attempt 2KiB + 1 ==> total 2KiB + 1
+ 2 * KiB, 4 * KiB, // will attempt 8KiB + 1 ==> total 10KiB + 2
+ 8 * KiB, 16 * KiB, // will attempt 32KiB + 1 ==> total 42KiB + 3
+ 32 * KiB, 64 * KiB, // will attempt 128KiB + 1 ==> total 170KiB + 4
+ 128 * KiB, 256 * KiB, // will attempt 512KiB + 1 ==> total 682KiB + 5
+ 512 * KiB, 1 * MiB, // will attempt 2MiB + 1 ==> total 2M + 682K + 6
+ 2 * MiB, 4 * MiB, // will attempt 8MiB + 1 ==> total 10M + 682K + 7
+ -(10 * MiB + 682 * KiB + 7)},
+ // try to avoid every ceiling again, except on our last fill.
+ {2 * KiB + 1, // will attempt 2KiB + 1 ==> total 2KiB + 1
+ 2 * KiB, 4 * KiB, // will attempt 8KiB + 1 ==> total 10KiB + 2
+ 8 * KiB, 16 * KiB, // will attempt 32KiB + 1 ==> total 42KiB + 3
+ 32 * KiB, 64 * KiB, // will attempt 128KiB + 1 ==> total 170KiB + 4
+ 128 * KiB, 256 * KiB, // will attempt 512KiB + 1 ==> total 682KiB + 5
+ 512 * KiB, 1 * MiB, // will attempt 2MiB + 1 ==> total 2M + 682K + 6
+ 2 * MiB, 4 * MiB - 1, // will attempt 8MiB ==> total 10M + 682K + 6
+ -(10 * MiB + 682 * KiB + 6)},
+
+ // try to hit ceilings on the way multiple times
+ {512 * KiB + 1, 256 * KiB, 128 * KiB, 128 * KiB - 1, // 1 MiB buffer
+ 512 * KiB + 1, 256 * KiB, 128 * KiB, 128 * KiB - 1, // 2 MiB buffer
+ 1 * MiB + 1, 512 * KiB, 256 * KiB, 256 * KiB - 1, // 4 MiB buffer
+ 2 * MiB + 1, 1 * MiB, 512 * KiB, // 8 MiB buffer
+ // we'll make a parse attempt at every parse call
+ -(45 * MiB + 12)},
+ };
+ const int testcount = sizeof(testcases) / sizeof(testcases[0]);
+ for (int test_i = 0; test_i < testcount; test_i++) {
+ const int *fillsize = testcases[test_i];
+ XML_Parser parser = XML_ParserCreate(NULL);
+ assert_true(parser != NULL);
+ g_parseAttempts = 0;
+
+ CharData storage;
+ CharData_Init(&storage);
+ XML_SetUserData(parser, &storage);
+ XML_SetStartElementHandler(parser, start_element_event_handler);
+
+ int worstcase_bytes = 0; // sum of (buffered bytes at each XML_Parse call)
+ int scanned_bytes = 0; // sum of (buffered bytes at each actual parse)
+ int offset = 0;
+ while (*fillsize >= 0) {
+ assert_true(offset + *fillsize <= document_length); // or test is invalid
+ const unsigned attempts_before = g_parseAttempts;
+ const enum XML_Status status
+ = XML_Parse(parser, &document[offset], *fillsize, XML_FALSE);
+ if (status != XML_STATUS_OK) {
+ xml_failure(parser);
+ }
+ offset += *fillsize;
+ fillsize++;
+ assert_true(offset <= INT_MAX - worstcase_bytes); // avoid overflow
+ worstcase_bytes += offset; // we might've tried to parse all pending bytes
+ if (g_parseAttempts != attempts_before) {
+ assert_true(g_parseAttempts == attempts_before + 1); // max 1/XML_Parse
+ assert_true(offset <= INT_MAX - scanned_bytes); // avoid overflow
+ scanned_bytes += offset; // we *did* try to parse all pending bytes
+ }
+ }
+ assert_true(storage.count == 1); // the big token should've been parsed
+ assert_true(scanned_bytes > 0); // test-the-test: does our counter work?
+ if (g_reparseDeferralEnabledDefault) {
+ // heuristic is enabled; some XML_Parse calls may have deferred reparsing
+ const int max_bytes_scanned = -*fillsize;
+ if (scanned_bytes > max_bytes_scanned) {
+ fprintf(stderr,
+ "bytes scanned in parse attempts: actual=%d limit=%d \n",
+ scanned_bytes, max_bytes_scanned);
+ fail("too many bytes scanned in parse attempts");
+ }
+ assert_true(scanned_bytes <= worstcase_bytes);
+ } else {
+ // heuristic is disabled; every XML_Parse() will have reparsed
+ assert_true(scanned_bytes == worstcase_bytes);
+ }
+
+ XML_ParserFree(parser);
+ }
+ free(document);
+}
+END_TEST
+
+
/*
* Namespaces tests.
*/
@@ -6902,13 +7529,13 @@ START_TEST(test_return_ns_triplet) {
if (_XML_Parse_SINGLE_BYTES(g_parser, text, (int)strlen(text), XML_FALSE)
== XML_STATUS_ERROR)
xml_failure(g_parser);
- if (! triplet_start_flag)
- fail("triplet_start_checker not invoked");
/* Check that unsetting "return triplets" fails while still parsing */
XML_SetReturnNSTriplet(g_parser, XML_FALSE);
if (_XML_Parse_SINGLE_BYTES(g_parser, epilog, (int)strlen(epilog), XML_TRUE)
== XML_STATUS_ERROR)
xml_failure(g_parser);
+ if (! triplet_start_flag)
+ fail("triplet_start_checker not invoked");
if (! triplet_end_flag)
fail("triplet_end_checker not invoked");
if (dummy_handler_flags
@@ -12219,6 +12846,7 @@ make_suite(void) {
#if defined(XML_CONTEXT_BYTES)
tcase_add_test(tc_basic, test_get_buffer_3_overflow);
#endif
+ tcase_add_test(tc_basic, test_getbuffer_allocates_on_zero_len);
tcase_add_test(tc_basic, test_byte_info_at_end);
tcase_add_test(tc_basic, test_byte_info_at_error);
tcase_add_test(tc_basic, test_byte_info_at_cdata);
@@ -12337,7 +12965,14 @@ make_suite(void) {
tcase_add_test__ifdef_xml_dtd(tc_basic,
test_pool_integrity_with_unfinished_attr);
tcase_add_test(tc_basic, test_nested_entity_suspend);
-
+ tcase_add_test(tc_basic, test_big_tokens_take_linear_time);
+ tcase_add_test(tc_basic, test_set_reparse_deferral);
+ tcase_add_test(tc_basic, test_reparse_deferral_is_inherited);
+ tcase_add_test(tc_basic, test_set_reparse_deferral_on_null_parser);
+ tcase_add_test(tc_basic, test_set_reparse_deferral_on_the_fly);
+ tcase_add_test(tc_basic, test_set_bad_reparse_option);
+ tcase_add_test(tc_basic, test_bypass_heuristic_when_close_to_bufsize);
+ tcase_add_test(tc_basic, test_varying_buffer_fills);
suite_add_tcase(s, tc_namespace);
tcase_add_checked_fixture(tc_namespace, namespace_setup, namespace_teardown);
tcase_add_test(tc_namespace, test_return_ns_triplet);
diff --git a/expat/xmlwf/xmlwf.c b/expat/xmlwf/xmlwf.c
index 471f2a2..7c62919 100644
--- a/expat/xmlwf/xmlwf.c
+++ b/expat/xmlwf/xmlwf.c
@@ -914,6 +914,9 @@ usage(const XML_Char *prog, int rc) {
T(" -a FACTOR set maximum tolerated [a]mplification factor (default: 100.0)\n")
T(" -b BYTES set number of output [b]ytes needed to activate (default: 8 MiB)\n")
T("\n")
+ T("reparse deferral:\n")
+ T(" -q disable reparse deferral, and allow [q]uadratic parse runtime with large tokens\n")
+ T("\n")
T("info arguments:\n")
T(" -h show this [h]elp message and exit\n")
T(" -v show program's [v]ersion number and exit\n")
@@ -967,6 +970,8 @@ tmain(int argc, XML_Char **argv) {
unsigned long long attackThresholdBytes;
XML_Bool attackThresholdGiven = XML_FALSE;
+ XML_Bool disableDeferral = XML_FALSE;
+
int exitCode = XMLWF_EXIT_SUCCESS;
enum XML_ParamEntityParsing paramEntityParsing
= XML_PARAM_ENTITY_PARSING_NEVER;
@@ -1089,6 +1094,11 @@ tmain(int argc, XML_Char **argv) {
#endif
break;
}
+ case T('q'): {
+ disableDeferral = XML_TRUE;
+ j++;
+ break;
+ }
case T('\0'):
if (j > 1) {
i++;
@@ -1134,6 +1144,16 @@ tmain(int argc, XML_Char **argv) {
#endif
}
+ if (disableDeferral) {
+ const XML_Bool success = XML_SetReparseDeferralEnabled(parser, XML_FALSE);
+ if (! success) {
+ // This prevents tperror(..) from reporting misleading "[..]: Success"
+ errno = EINVAL;
+ tperror(T("Failed to disable reparse deferral"));
+ exit(XMLWF_EXIT_INTERNAL_ERROR);
+ }
+ }
+
if (requireStandalone)
XML_SetNotStandaloneHandler(parser, notStandalone);
XML_SetParamEntityParsing(parser, paramEntityParsing);
diff --git a/expat/xmlwf/xmlwf_helpgen.py b/expat/xmlwf/xmlwf_helpgen.py
index c2a527f..1bd0a0a 100755
--- a/expat/xmlwf/xmlwf_helpgen.py
+++ b/expat/xmlwf/xmlwf_helpgen.py
@@ -81,6 +81,10 @@ billion_laughs.add_argument('-a', metavar='FACTOR',
help='set maximum tolerated [a]mplification factor (default: 100.0)')
billion_laughs.add_argument('-b', metavar='BYTES', help='set number of output [b]ytes needed to activate (default: 8 MiB)')
+reparse_deferral = parser.add_argument_group('reparse deferral')
+reparse_deferral.add_argument('-q', metavar='FACTOR',
+ help='disable reparse deferral, and allow [q]uadratic parse runtime with large tokens')
+
parser.add_argument('files', metavar='FILE', nargs='*', help='file to process (default: STDIN)')
info = parser.add_argument_group('info arguments')
diff --git a/testdata/largefiles/aaaaaa_attr.xml b/testdata/largefiles/aaaaaa_attr.xml
new file mode 100644
index 0000000..66e3d25
--- /dev/null
+++ b/testdata/largefiles/aaaaaa_attr.xml
@@ -0,0 +1 @@
+<myFile><attack value="ACHARS"></attack></myFile>
\ No newline at end of file
diff --git a/testdata/largefiles/aaaaaa_cdata.xml b/testdata/largefiles/aaaaaa_cdata.xml
new file mode 100644
index 0000000..66f64bd
--- /dev/null
+++ b/testdata/largefiles/aaaaaa_cdata.xml
@@ -0,0 +1 @@
+<myFile><attack><![CDATA[ value: ACHARS ]]></attack></myFile>
\ No newline at end of file
diff --git a/testdata/largefiles/aaaaaa_comment.xml b/testdata/largefiles/aaaaaa_comment.xml
new file mode 100644
index 0000000..bb9af13
--- /dev/null
+++ b/testdata/largefiles/aaaaaa_comment.xml
@@ -0,0 +1 @@
+<myFile><attack><!-- value: ACHARS --></attack></myFile>
\ No newline at end of file
diff --git a/testdata/largefiles/aaaaaa_tag.xml b/testdata/largefiles/aaaaaa_tag.xml
new file mode 100644
index 0000000..946f701
--- /dev/null
+++ b/testdata/largefiles/aaaaaa_tag.xml
@@ -0,0 +1 @@
+<myFile><attack><ACHARS /></attack></myFile>
\ No newline at end of file
diff --git a/testdata/largefiles/aaaaaa_text.xml b/testdata/largefiles/aaaaaa_text.xml
new file mode 100644
index 0000000..e266acb
--- /dev/null
+++ b/testdata/largefiles/aaaaaa_text.xml
@@ -0,0 +1 @@
+<myFile><attack>ACHARS</attack></myFile>
\ No newline at end of file
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