diff options
Diffstat (limited to 'Modules/expat/xmlparse.c')
| -rw-r--r-- | Modules/expat/xmlparse.c | 530 |
1 files changed, 458 insertions, 72 deletions
diff --git a/Modules/expat/xmlparse.c b/Modules/expat/xmlparse.c index daec151..b703e61 100644 --- a/Modules/expat/xmlparse.c +++ b/Modules/expat/xmlparse.c @@ -1,10 +1,12 @@ /* Copyright (c) 1998, 1999, 2000 Thai Open Source Software Center Ltd See the file COPYING for copying permission. - 77fea421d361dca90041d0040ecf1dca651167fadf2af79e990e35168d70d933 (2.2.1+) + 101bfd65d1ff3d1511cf6671e6aae65f82cd97df6f4da137d46d510731830ad9 (2.2.3+) */ -#define _GNU_SOURCE 1 /* syscall prototype */ +#if !defined(_GNU_SOURCE) +# define _GNU_SOURCE 1 /* syscall prototype */ +#endif #include <stddef.h> #include <string.h> /* memset(), memcpy() */ @@ -19,6 +21,8 @@ #include <sys/time.h> /* gettimeofday() */ #include <sys/types.h> /* getpid() */ #include <unistd.h> /* getpid() */ +#include <fcntl.h> /* O_RDONLY */ +#include <errno.h> #endif #define XML_BUILDING_EXPAT 1 @@ -33,6 +37,57 @@ #include "expat.h" #include "siphash.h" +#if defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) +# if defined(HAVE_GETRANDOM) +# include <sys/random.h> /* getrandom */ +# else +# include <unistd.h> /* syscall */ +# include <sys/syscall.h> /* SYS_getrandom */ +# endif +# if ! defined(GRND_NONBLOCK) +# define GRND_NONBLOCK 0x0001 +# endif /* defined(GRND_NONBLOCK) */ +#endif /* defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) */ + +#if defined(HAVE_LIBBSD) \ + && (defined(HAVE_ARC4RANDOM_BUF) || defined(HAVE_ARC4RANDOM)) +# include <bsd/stdlib.h> +#endif + +#if defined(_WIN32) && !defined(LOAD_LIBRARY_SEARCH_SYSTEM32) +# define LOAD_LIBRARY_SEARCH_SYSTEM32 0x00000800 +#endif + +#if !defined(HAVE_GETRANDOM) && !defined(HAVE_SYSCALL_GETRANDOM) \ + && !defined(HAVE_ARC4RANDOM_BUF) && !defined(HAVE_ARC4RANDOM) \ + && !defined(XML_DEV_URANDOM) \ + && !defined(_WIN32) \ + && !defined(XML_POOR_ENTROPY) +# error \ + You do not have support for any sources of high quality entropy \ + enabled. For end user security, that is probably not what you want. \ + \ + Your options include: \ + * Linux + glibc >=2.25 (getrandom): HAVE_GETRANDOM, \ + * Linux + glibc <2.25 (syscall SYS_getrandom): HAVE_SYSCALL_GETRANDOM, \ + * BSD / macOS >=10.7 (arc4random_buf): HAVE_ARC4RANDOM_BUF, \ + * BSD / macOS <10.7 (arc4random): HAVE_ARC4RANDOM, \ + * libbsd (arc4random_buf): HAVE_ARC4RANDOM_BUF + HAVE_LIBBSD, \ + * libbsd (arc4random): HAVE_ARC4RANDOM + HAVE_LIBBSD, \ + * Linux / BSD / macOS (/dev/urandom): XML_DEV_URANDOM \ + * Windows (RtlGenRandom): _WIN32. \ + \ + If insist on not using any of these, bypass this error by defining \ + XML_POOR_ENTROPY; you have been warned. \ + \ + For CMake, one way to pass the define is: \ + cmake -DCMAKE_C_FLAGS="-pipe -O2 -DHAVE_SYSCALL_GETRANDOM" . \ + \ + If you have reasons to patch this detection code away or need changes \ + to the build system, please open a bug. Thank you! +#endif + + #ifdef XML_UNICODE #define XML_ENCODE_MAX XML_UTF16_ENCODE_MAX #define XmlConvert XmlUtf16Convert @@ -436,6 +491,9 @@ static ELEMENT_TYPE * getElementType(XML_Parser parser, const ENCODING *enc, const char *ptr, const char *end); +static XML_Char *copyString(const XML_Char *s, + const XML_Memory_Handling_Suite *memsuite); + static unsigned long generate_hash_secret_salt(XML_Parser parser); static XML_Bool startParsing(XML_Parser parser); @@ -696,21 +754,13 @@ static const XML_Char implicitContext[] = { #if defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) -# include <errno.h> - -# if defined(HAVE_GETRANDOM) -# include <sys/random.h> /* getrandom */ -# else -# include <unistd.h> /* syscall */ -# include <sys/syscall.h> /* SYS_getrandom */ -# endif /* Obtain entropy on Linux 3.17+ */ static int -writeRandomBytes_getrandom(void * target, size_t count) { +writeRandomBytes_getrandom_nonblock(void * target, size_t count) { int success = 0; /* full count bytes written? */ size_t bytesWrittenTotal = 0; - const unsigned int getrandomFlags = 0; + const unsigned int getrandomFlags = GRND_NONBLOCK; do { void * const currentTarget = (void*)((char*)target + bytesWrittenTotal); @@ -728,7 +778,7 @@ writeRandomBytes_getrandom(void * target, size_t count) { if (bytesWrittenTotal >= count) success = 1; } - } while (! success && (errno == EINTR || errno == EAGAIN)); + } while (! success && (errno == EINTR)); return success; } @@ -736,12 +786,67 @@ writeRandomBytes_getrandom(void * target, size_t count) { #endif /* defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) */ +#if ! defined(_WIN32) && defined(XML_DEV_URANDOM) + +/* Extract entropy from /dev/urandom */ +static int +writeRandomBytes_dev_urandom(void * target, size_t count) { + int success = 0; /* full count bytes written? */ + size_t bytesWrittenTotal = 0; + + const int fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) { + return 0; + } + + do { + void * const currentTarget = (void*)((char*)target + bytesWrittenTotal); + const size_t bytesToWrite = count - bytesWrittenTotal; + + const ssize_t bytesWrittenMore = read(fd, currentTarget, bytesToWrite); + + if (bytesWrittenMore > 0) { + bytesWrittenTotal += bytesWrittenMore; + if (bytesWrittenTotal >= count) + success = 1; + } + } while (! success && (errno == EINTR)); + + close(fd); + return success; +} + +#endif /* ! defined(_WIN32) && defined(XML_DEV_URANDOM) */ + + +#if defined(HAVE_ARC4RANDOM) + +static void +writeRandomBytes_arc4random(void * target, size_t count) { + size_t bytesWrittenTotal = 0; + + while (bytesWrittenTotal < count) { + const uint32_t random32 = arc4random(); + size_t i = 0; + + for (; (i < sizeof(random32)) && (bytesWrittenTotal < count); + i++, bytesWrittenTotal++) { + const uint8_t random8 = (uint8_t)(random32 >> (i * 8)); + ((uint8_t *)target)[bytesWrittenTotal] = random8; + } + } +} + +#endif /* defined(HAVE_ARC4RANDOM) */ + + #ifdef _WIN32 typedef BOOLEAN (APIENTRY *RTLGENRANDOM_FUNC)(PVOID, ULONG); +HMODULE _Expat_LoadLibrary(LPCTSTR filename); /* see loadlibrary.c */ /* Obtain entropy on Windows XP / Windows Server 2003 and later. - * Hint on RtlGenRandom and the following article from libsodioum. + * Hint on RtlGenRandom and the following article from libsodium. * * Michael Howard: Cryptographically Secure Random number on Windows without using CryptoAPI * https://blogs.msdn.microsoft.com/michael_howard/2005/01/14/cryptographically-secure-random-number-on-windows-without-using-cryptoapi/ @@ -749,7 +854,7 @@ typedef BOOLEAN (APIENTRY *RTLGENRANDOM_FUNC)(PVOID, ULONG); static int writeRandomBytes_RtlGenRandom(void * target, size_t count) { int success = 0; /* full count bytes written? */ - const HMODULE advapi32 = LoadLibrary("ADVAPI32.DLL"); + const HMODULE advapi32 = _Expat_LoadLibrary(TEXT("ADVAPI32.DLL")); if (advapi32) { const RTLGENRANDOM_FUNC RtlGenRandom @@ -768,6 +873,8 @@ writeRandomBytes_RtlGenRandom(void * target, size_t count) { #endif /* _WIN32 */ +#if ! defined(HAVE_ARC4RANDOM_BUF) && ! defined(HAVE_ARC4RANDOM) + static unsigned long gather_time_entropy(void) { @@ -780,16 +887,20 @@ gather_time_entropy(void) int gettimeofday_res; gettimeofday_res = gettimeofday(&tv, NULL); + +#if defined(NDEBUG) + (void)gettimeofday_res; +#else assert (gettimeofday_res == 0); +#endif /* defined(NDEBUG) */ /* Microseconds time is <20 bits entropy */ return tv.tv_usec; #endif } -#if defined(HAVE_ARC4RANDOM_BUF) && defined(HAVE_LIBBSD) -# include <bsd/stdlib.h> -#endif +#endif /* ! defined(HAVE_ARC4RANDOM_BUF) && ! defined(HAVE_ARC4RANDOM) */ + static unsigned long ENTROPY_DEBUG(const char * label, unsigned long entropy) { @@ -808,10 +919,12 @@ generate_hash_secret_salt(XML_Parser parser) { unsigned long entropy; (void)parser; -#if defined(HAVE_ARC4RANDOM_BUF) || defined(__CloudABI__) - (void)gather_time_entropy; +#if defined(HAVE_ARC4RANDOM_BUF) arc4random_buf(&entropy, sizeof(entropy)); return ENTROPY_DEBUG("arc4random_buf", entropy); +#elif defined(HAVE_ARC4RANDOM) + writeRandomBytes_arc4random((void *)&entropy, sizeof(entropy)); + return ENTROPY_DEBUG("arc4random", entropy); #else /* Try high quality providers first .. */ #ifdef _WIN32 @@ -819,10 +932,15 @@ generate_hash_secret_salt(XML_Parser parser) return ENTROPY_DEBUG("RtlGenRandom", entropy); } #elif defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) - if (writeRandomBytes_getrandom((void *)&entropy, sizeof(entropy))) { + if (writeRandomBytes_getrandom_nonblock((void *)&entropy, sizeof(entropy))) { return ENTROPY_DEBUG("getrandom", entropy); } #endif +#if ! defined(_WIN32) && defined(XML_DEV_URANDOM) + if (writeRandomBytes_dev_urandom((void *)&entropy, sizeof(entropy))) { + return ENTROPY_DEBUG("/dev/urandom", entropy); + } +#endif /* ! defined(_WIN32) && defined(XML_DEV_URANDOM) */ /* .. and self-made low quality for backup: */ /* Process ID is 0 bits entropy if attacker has local access */ @@ -833,7 +951,7 @@ generate_hash_secret_salt(XML_Parser parser) return ENTROPY_DEBUG("fallback(4)", entropy * 2147483647); } else { return ENTROPY_DEBUG("fallback(8)", - entropy * (unsigned long)2305843009213693951); + entropy * (unsigned long)2305843009213693951ULL); } #endif } @@ -962,6 +1080,8 @@ parserCreate(const XML_Char *encodingName, nsAttsVersion = 0; nsAttsPower = 0; + protocolEncodingName = NULL; + poolInit(&tempPool, &(parser->m_mem)); poolInit(&temp2Pool, &(parser->m_mem)); parserInit(parser, encodingName); @@ -988,9 +1108,9 @@ parserInit(XML_Parser parser, const XML_Char *encodingName) { processor = prologInitProcessor; XmlPrologStateInit(&prologState); - protocolEncodingName = (encodingName != NULL - ? poolCopyString(&tempPool, encodingName) - : NULL); + if (encodingName != NULL) { + protocolEncodingName = copyString(encodingName, &(parser->m_mem)); + } curBase = NULL; XmlInitEncoding(&initEncoding, &encoding, 0); userData = NULL; @@ -1103,6 +1223,8 @@ XML_ParserReset(XML_Parser parser, const XML_Char *encodingName) unknownEncodingRelease(unknownEncodingData); poolClear(&tempPool); poolClear(&temp2Pool); + FREE((void *)protocolEncodingName); + protocolEncodingName = NULL; parserInit(parser, encodingName); dtdReset(_dtd, &parser->m_mem); return XML_TRUE; @@ -1119,10 +1241,16 @@ XML_SetEncoding(XML_Parser parser, const XML_Char *encodingName) */ if (ps_parsing == XML_PARSING || ps_parsing == XML_SUSPENDED) return XML_STATUS_ERROR; + + /* Get rid of any previous encoding name */ + FREE((void *)protocolEncodingName); + if (encodingName == NULL) + /* No new encoding name */ protocolEncodingName = NULL; else { - protocolEncodingName = poolCopyString(&tempPool, encodingName); + /* Copy the new encoding name into allocated memory */ + protocolEncodingName = copyString(encodingName, &(parser->m_mem)); if (!protocolEncodingName) return XML_STATUS_ERROR; } @@ -1357,6 +1485,7 @@ XML_ParserFree(XML_Parser parser) destroyBindings(inheritedBindings, parser); poolDestroy(&tempPool); poolDestroy(&temp2Pool); + FREE((void *)protocolEncodingName); #ifdef XML_DTD /* external parameter entity parsers share the DTD structure parser->m_dtd with the root parser, so we must not destroy it @@ -1748,7 +1877,8 @@ enum XML_Status XMLCALL XML_Parse(XML_Parser parser, const char *s, int len, int isFinal) { if ((parser == NULL) || (len < 0) || ((s == NULL) && (len != 0))) { - errorCode = XML_ERROR_INVALID_ARGUMENT; + if (parser != NULL) + parser->m_errorCode = XML_ERROR_INVALID_ARGUMENT; return XML_STATUS_ERROR; } switch (ps_parsing) { @@ -1783,9 +1913,22 @@ XML_Parse(XML_Parser parser, const char *s, int len, int isFinal) if (errorCode == XML_ERROR_NONE) { switch (ps_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(encoding, positionPtr, bufferPtr, &position); positionPtr = bufferPtr; return XML_STATUS_SUSPENDED; + /* LCOV_EXCL_STOP */ case XML_INITIALIZED: case XML_PARSING: ps_parsing = XML_FINISHED; @@ -2974,9 +3117,17 @@ doContent(XML_Parser parser, return XML_ERROR_NO_MEMORY; break; default: + /* All of the tokens produced by XmlContentTok() have their own + * explicit cases, so this default is not strictly necessary. + * However it is a useful safety net, so we retain the code and + * simply exclude it from the coverage tests. + * + * LCOV_EXCL_START + */ if (defaultHandler) reportDefault(parser, enc, s, next); break; + /* LCOV_EXCL_STOP */ } *eventPP = s = next; switch (ps_parsing) { @@ -3067,13 +3218,17 @@ storeAtts(XML_Parser parser, const ENCODING *enc, #endif attsSize = n + nDefaultAtts + INIT_ATTS_SIZE; temp = (ATTRIBUTE *)REALLOC((void *)atts, attsSize * sizeof(ATTRIBUTE)); - if (temp == NULL) + if (temp == NULL) { + attsSize = oldAttsSize; return XML_ERROR_NO_MEMORY; + } atts = temp; #ifdef XML_ATTR_INFO temp2 = (XML_AttrInfo *)REALLOC((void *)attInfo, attsSize * sizeof(XML_AttrInfo)); - if (temp2 == NULL) + if (temp2 == NULL) { + attsSize = oldAttsSize; return XML_ERROR_NO_MEMORY; + } attInfo = temp2; #endif if (n > oldAttsSize) @@ -3210,6 +3365,7 @@ storeAtts(XML_Parser parser, const ENCODING *enc, int j; /* hash table index */ unsigned long version = nsAttsVersion; int nsAttsSize = (int)1 << nsAttsPower; + unsigned char oldNsAttsPower = nsAttsPower; /* size of hash table must be at least 2 * (# of prefixed attributes) */ if ((nPrefixes << 1) >> nsAttsPower) { /* true for nsAttsPower = 0 */ NS_ATT *temp; @@ -3219,8 +3375,11 @@ storeAtts(XML_Parser parser, const ENCODING *enc, nsAttsPower = 3; nsAttsSize = (int)1 << nsAttsPower; temp = (NS_ATT *)REALLOC(nsAtts, nsAttsSize * sizeof(NS_ATT)); - if (!temp) + if (!temp) { + /* Restore actual size of memory in nsAtts */ + nsAttsPower = oldNsAttsPower; return XML_ERROR_NO_MEMORY; + } nsAtts = temp; version = 0; /* force re-initialization of nsAtts hash table */ } @@ -3247,8 +3406,23 @@ storeAtts(XML_Parser parser, const ENCODING *enc, ((XML_Char *)s)[-1] = 0; /* clear flag */ id = (ATTRIBUTE_ID *)lookup(parser, &dtd->attributeIds, s, 0); - if (!id || !id->prefix) - return XML_ERROR_NO_MEMORY; + if (!id || !id->prefix) { + /* This code is walking through the appAtts array, dealing + * with (in this case) a prefixed attribute name. To be in + * the array, the attribute must have already been bound, so + * has to have passed through the hash table lookup once + * already. That implies that an entry for it already + * exists, so the lookup above will return a pointer to + * already allocated memory. There is no opportunaity for + * the allocator to fail, so the condition above cannot be + * fulfilled. + * + * Since it is difficult to be certain that the above + * analysis is complete, we retain the test and merely + * remove the code from coverage tests. + */ + return XML_ERROR_NO_MEMORY; /* LCOV_EXCL_LINE */ + } b = id->prefix->binding; if (!b) return XML_ERROR_UNBOUND_PREFIX; @@ -3625,8 +3799,16 @@ doCdataSection(XML_Parser parser, } return XML_ERROR_UNCLOSED_CDATA_SECTION; default: + /* Every token returned by XmlCdataSectionTok() has its own + * explicit case, so this default case will never be executed. + * We retain it as a safety net and exclude it from the coverage + * statistics. + * + * LCOV_EXCL_START + */ *eventPP = next; return XML_ERROR_UNEXPECTED_STATE; + /* LCOV_EXCL_STOP */ } *eventPP = s = next; @@ -3686,8 +3868,20 @@ doIgnoreSection(XML_Parser parser, eventEndPP = &eventEndPtr; } else { + /* It's not entirely clear, but it seems the following two lines + * of code cannot be executed. The only occasions on which 'enc' + * is not 'parser->m_encoding' are when this function is called + * from the internal entity processing, and IGNORE sections are an + * error in internal entities. + * + * Since it really isn't clear that this is true, we keep the code + * and just remove it from our coverage tests. + * + * LCOV_EXCL_START + */ eventPP = &(openInternalEntities->internalEventPtr); eventEndPP = &(openInternalEntities->internalEventEndPtr); + /* LCOV_EXCL_STOP */ } *eventPP = s; *startPtr = NULL; @@ -3720,8 +3914,16 @@ doIgnoreSection(XML_Parser parser, } return XML_ERROR_SYNTAX; /* XML_ERROR_UNCLOSED_IGNORE_SECTION */ default: + /* All of the tokens that XmlIgnoreSectionTok() returns have + * explicit cases to handle them, so this default case is never + * executed. We keep it as a safety net anyway, and remove it + * from our test coverage statistics. + * + * LCOV_EXCL_START + */ *eventPP = next; return XML_ERROR_UNEXPECTED_STATE; + /* LCOV_EXCL_STOP */ } /* not reached */ } @@ -3734,6 +3936,7 @@ initializeEncoding(XML_Parser parser) const char *s; #ifdef XML_UNICODE char encodingBuf[128]; + /* See comments abount `protoclEncodingName` in parserInit() */ if (!protocolEncodingName) s = NULL; else { @@ -3817,7 +4020,14 @@ processXmlDecl(XML_Parser parser, int isGeneralTextEntity, reportDefault(parser, encoding, s, next); if (protocolEncodingName == NULL) { if (newEncoding) { - if (newEncoding->minBytesPerChar != encoding->minBytesPerChar) { + /* Check that the specified encoding does not conflict with what + * the parser has already deduced. Do we have the same number + * of bytes in the smallest representation of a character? If + * this is UTF-16, is it the same endianness? + */ + if (newEncoding->minBytesPerChar != encoding->minBytesPerChar + || (newEncoding->minBytesPerChar == 2 && + newEncoding != encoding)) { eventPtr = encodingName; return XML_ERROR_INCORRECT_ENCODING; } @@ -3962,15 +4172,14 @@ entityValueInitProcessor(XML_Parser parser, result = processXmlDecl(parser, 0, start, next); if (result != XML_ERROR_NONE) return result; - switch (ps_parsing) { - case XML_SUSPENDED: - *nextPtr = next; - return XML_ERROR_NONE; - case XML_FINISHED: + /* At this point, ps_parsing cannot be XML_SUSPENDED. For that + * to happen, a parameter entity parsing handler must have + * attempted to suspend the parser, which fails and raises an + * error. The parser can be aborted, but can't be suspended. + */ + if (ps_parsing == XML_FINISHED) return XML_ERROR_ABORTED; - default: - *nextPtr = next; - } + *nextPtr = next; /* stop scanning for text declaration - we found one */ processor = entityValueProcessor; return entityValueProcessor(parser, next, end, nextPtr); @@ -4293,8 +4502,14 @@ doProlog(XML_Parser parser, &dtd->paramEntities, externalSubsetName, sizeof(ENTITY)); - if (!entity) - return XML_ERROR_NO_MEMORY; + if (!entity) { + /* The external subset name "#" will have already been + * inserted into the hash table at the start of the + * external entity parsing, so no allocation will happen + * and lookup() cannot fail. + */ + return XML_ERROR_NO_MEMORY; /* LCOV_EXCL_LINE */ + } if (useForeignDTD) entity->base = curBase; dtd->paramEntityRead = XML_FALSE; @@ -4773,8 +4988,10 @@ doProlog(XML_Parser parser, if (prologState.level >= groupSize) { if (groupSize) { char *temp = (char *)REALLOC(groupConnector, groupSize *= 2); - if (temp == NULL) + if (temp == NULL) { + groupSize /= 2; return XML_ERROR_NO_MEMORY; + } groupConnector = temp; if (dtd->scaffIndex) { int *temp = (int *)REALLOC(dtd->scaffIndex, @@ -4786,8 +5003,10 @@ doProlog(XML_Parser parser, } else { groupConnector = (char *)MALLOC(groupSize = 32); - if (!groupConnector) + if (!groupConnector) { + groupSize = 0; return XML_ERROR_NO_MEMORY; + } } } groupConnector[prologState.level] = 0; @@ -4850,8 +5069,29 @@ doProlog(XML_Parser parser, : !dtd->hasParamEntityRefs)) { if (!entity) return XML_ERROR_UNDEFINED_ENTITY; - else if (!entity->is_internal) - return XML_ERROR_ENTITY_DECLARED_IN_PE; + else if (!entity->is_internal) { + /* It's hard to exhaustively search the code to be sure, + * but there doesn't seem to be a way of executing the + * following line. There are two cases: + * + * If 'standalone' is false, the DTD must have no + * parameter entities or we wouldn't have passed the outer + * 'if' statement. That measn the only entity in the hash + * table is the external subset name "#" which cannot be + * given as a parameter entity name in XML syntax, so the + * lookup must have returned NULL and we don't even reach + * the test for an internal entity. + * + * If 'standalone' is true, it does not seem to be + * possible to create entities taking this code path that + * are not internal entities, so fail the test above. + * + * Because this analysis is very uncertain, the code is + * being left in place and merely removed from the + * coverage test statistics. + */ + return XML_ERROR_ENTITY_DECLARED_IN_PE; /* LCOV_EXCL_LINE */ + } } else if (!entity) { dtd->keepProcessing = dtd->standalone; @@ -5323,11 +5563,15 @@ appendAttributeValue(XML_Parser parser, const ENCODING *enc, XML_Bool isCdata, && (poolLength(pool) == 0 || poolLastChar(pool) == 0x20)) break; n = XmlEncode(n, (ICHAR *)buf); - if (!n) { - if (enc == encoding) - eventPtr = ptr; - return XML_ERROR_BAD_CHAR_REF; - } + /* The XmlEncode() functions can never return 0 here. That + * error return happens if the code point passed in is either + * negative or greater than or equal to 0x110000. The + * XmlCharRefNumber() functions will all return a number + * strictly less than 0x110000 or a negative value if an error + * occurred. The negative value is intercepted above, so + * XmlEncode() is never passed a value it might return an + * error for. + */ for (i = 0; i < n; i++) { if (!poolAppendChar(pool, buf[i])) return XML_ERROR_NO_MEMORY; @@ -5401,8 +5645,26 @@ appendAttributeValue(XML_Parser parser, const ENCODING *enc, XML_Bool isCdata, break; } if (entity->open) { - if (enc == encoding) - eventPtr = ptr; + if (enc == encoding) { + /* It does not appear that this line can be executed. + * + * The "if (entity->open)" check catches recursive entity + * definitions. In order to be called with an open + * entity, it must have gone through this code before and + * been through the recursive call to + * appendAttributeValue() some lines below. That call + * sets the local encoding ("enc") to the parser's + * internal encoding (internal_utf8 or internal_utf16), + * which can never be the same as the principle encoding. + * It doesn't appear there is another code path that gets + * here with entity->open being TRUE. + * + * Since it is not certain that this logic is watertight, + * we keep the line and merely exclude it from coverage + * tests. + */ + eventPtr = ptr; /* LCOV_EXCL_LINE */ + } return XML_ERROR_RECURSIVE_ENTITY_REF; } if (entity->notation) { @@ -5429,9 +5691,21 @@ appendAttributeValue(XML_Parser parser, const ENCODING *enc, XML_Bool isCdata, } break; default: + /* The only token returned by XmlAttributeValueTok() that does + * not have an explicit case here is XML_TOK_PARTIAL_CHAR. + * Getting that would require an entity name to contain an + * incomplete XML character (e.g. \xE2\x82); however previous + * tokenisers will have already recognised and rejected such + * names before XmlAttributeValueTok() gets a look-in. This + * default case should be retained as a safety net, but the code + * excluded from coverage tests. + * + * LCOV_EXCL_START + */ if (enc == encoding) eventPtr = ptr; return XML_ERROR_UNEXPECTED_STATE; + /* LCOV_EXCL_STOP */ } ptr = next; } @@ -5564,12 +5838,15 @@ storeEntityValue(XML_Parser parser, goto endEntityValue; } n = XmlEncode(n, (ICHAR *)buf); - if (!n) { - if (enc == encoding) - eventPtr = entityTextPtr; - result = XML_ERROR_BAD_CHAR_REF; - goto endEntityValue; - } + /* The XmlEncode() functions can never return 0 here. That + * error return happens if the code point passed in is either + * negative or greater than or equal to 0x110000. The + * XmlCharRefNumber() functions will all return a number + * strictly less than 0x110000 or a negative value if an error + * occurred. The negative value is intercepted above, so + * XmlEncode() is never passed a value it might return an + * error for. + */ for (i = 0; i < n; i++) { if (pool->end == pool->ptr && !poolGrow(pool)) { result = XML_ERROR_NO_MEMORY; @@ -5590,10 +5867,18 @@ storeEntityValue(XML_Parser parser, result = XML_ERROR_INVALID_TOKEN; goto endEntityValue; default: + /* This default case should be unnecessary -- all the tokens + * that XmlEntityValueTok() can return have their own explicit + * cases -- but should be retained for safety. We do however + * exclude it from the coverage statistics. + * + * LCOV_EXCL_START + */ if (enc == encoding) eventPtr = entityTextPtr; result = XML_ERROR_UNEXPECTED_STATE; goto endEntityValue; + /* LCOV_EXCL_STOP */ } entityTextPtr = next; } @@ -5691,8 +5976,25 @@ reportDefault(XML_Parser parser, const ENCODING *enc, eventEndPP = &eventEndPtr; } else { + /* To get here, two things must be true; the parser must be + * using a character encoding that is not the same as the + * encoding passed in, and the encoding passed in must need + * conversion to the internal format (UTF-8 unless XML_UNICODE + * is defined). The only occasions on which the encoding passed + * in is not the same as the parser's encoding are when it is + * the internal encoding (e.g. a previously defined parameter + * entity, already converted to internal format). This by + * definition doesn't need conversion, so the whole branch never + * gets executed. + * + * For safety's sake we don't delete these lines and merely + * exclude them from coverage statistics. + * + * LCOV_EXCL_START + */ eventPP = &(openInternalEntities->internalEventPtr); eventEndPP = &(openInternalEntities->internalEventEndPtr); + /* LCOV_EXCL_STOP */ } do { ICHAR *dataPtr = (ICHAR *)dataBuf; @@ -5861,9 +6163,30 @@ getContext(XML_Parser parser) len = dtd->defaultPrefix.binding->uriLen; if (namespaceSeparator) len--; - for (i = 0; i < len; i++) - if (!poolAppendChar(&tempPool, dtd->defaultPrefix.binding->uri[i])) - return NULL; + for (i = 0; i < len; i++) { + if (!poolAppendChar(&tempPool, dtd->defaultPrefix.binding->uri[i])) { + /* Because of memory caching, I don't believe this line can be + * executed. + * + * This is part of a loop copying the default prefix binding + * URI into the parser's temporary string pool. Previously, + * that URI was copied into the same string pool, with a + * terminating NUL character, as part of setContext(). When + * the pool was cleared, that leaves a block definitely big + * enough to hold the URI on the free block list of the pool. + * The URI copy in getContext() therefore cannot run out of + * memory. + * + * If the pool is used between the setContext() and + * getContext() calls, the worst it can do is leave a bigger + * block on the front of the free list. Given that this is + * all somewhat inobvious and program logic can be changed, we + * don't delete the line but we do exclude it from the test + * coverage statistics. + */ + return NULL; /* LCOV_EXCL_LINE */ + } + } needSep = XML_TRUE; } @@ -5875,8 +6198,15 @@ getContext(XML_Parser parser) PREFIX *prefix = (PREFIX *)hashTableIterNext(&iter); if (!prefix) break; - if (!prefix->binding) - continue; + if (!prefix->binding) { + /* This test appears to be (justifiable) paranoia. There does + * not seem to be a way of injecting a prefix without a binding + * that doesn't get errored long before this function is called. + * The test should remain for safety's sake, so we instead + * exclude the following line from the coverage statistics. + */ + continue; /* LCOV_EXCL_LINE */ + } if (needSep && !poolAppendChar(&tempPool, CONTEXT_SEP)) return NULL; for (s = prefix->name; *s; s++) @@ -6547,8 +6877,20 @@ poolCopyString(STRING_POOL *pool, const XML_Char *s) static const XML_Char * poolCopyStringN(STRING_POOL *pool, const XML_Char *s, int n) { - if (!pool->ptr && !poolGrow(pool)) - return NULL; + if (!pool->ptr && !poolGrow(pool)) { + /* The following line is unreachable given the current usage of + * poolCopyStringN(). Currently it is called from exactly one + * place to copy the text of a simple general entity. By that + * point, the name of the entity is already stored in the pool, so + * pool->ptr cannot be NULL. + * + * If poolCopyStringN() is used elsewhere as it well might be, + * this line may well become executable again. Regardless, this + * sort of check shouldn't be removed lightly, so we just exclude + * it from the coverage statistics. + */ + return NULL; /* LCOV_EXCL_LINE */ + } for (; n > 0; --n, s++) { if (!poolAppendChar(pool, *s)) return NULL; @@ -6641,8 +6983,19 @@ poolGrow(STRING_POOL *pool) int blockSize = (int)((unsigned)(pool->end - pool->start)*2U); size_t bytesToAllocate; - if (blockSize < 0) - return XML_FALSE; + // NOTE: Needs to be calculated prior to calling `realloc` + // to avoid dangling pointers: + const ptrdiff_t offsetInsideBlock = pool->ptr - pool->start; + + if (blockSize < 0) { + /* This condition traps a situation where either more than + * INT_MAX/2 bytes have already been allocated. This isn't + * readily testable, since it is unlikely that an average + * machine will have that much memory, so we exclude it from the + * coverage statistics. + */ + return XML_FALSE; /* LCOV_EXCL_LINE */ + } bytesToAllocate = poolBytesToAllocateFor(blockSize); if (bytesToAllocate == 0) @@ -6654,7 +7007,7 @@ poolGrow(STRING_POOL *pool) return XML_FALSE; pool->blocks = temp; pool->blocks->size = blockSize; - pool->ptr = pool->blocks->s + (pool->ptr - pool->start); + pool->ptr = pool->blocks->s + offsetInsideBlock; pool->start = pool->blocks->s; pool->end = pool->start + blockSize; } @@ -6663,8 +7016,18 @@ poolGrow(STRING_POOL *pool) int blockSize = (int)(pool->end - pool->start); size_t bytesToAllocate; - if (blockSize < 0) - return XML_FALSE; + if (blockSize < 0) { + /* This condition traps a situation where either more than + * INT_MAX bytes have already been allocated (which is prevented + * by various pieces of program logic, not least this one, never + * mind the unlikelihood of actually having that much memory) or + * the pool control fields have been corrupted (which could + * conceivably happen in an extremely buggy user handler + * function). Either way it isn't readily testable, so we + * exclude it from the coverage statistics. + */ + return XML_FALSE; /* LCOV_EXCL_LINE */ + } if (blockSize < INIT_BLOCK_SIZE) blockSize = INIT_BLOCK_SIZE; @@ -6827,3 +7190,26 @@ getElementType(XML_Parser parser, } return ret; } + +static XML_Char * +copyString(const XML_Char *s, + const XML_Memory_Handling_Suite *memsuite) +{ + int charsRequired = 0; + XML_Char *result; + + /* First determine how long the string is */ + while (s[charsRequired] != 0) { + charsRequired++; + } + /* Include the terminator */ + charsRequired++; + + /* Now allocate space for the copy */ + result = memsuite->malloc_fcn(charsRequired * sizeof(XML_Char)); + if (result == NULL) + return NULL; + /* Copy the original into place */ + memcpy(result, s, charsRequired * sizeof(XML_Char)); + return result; +} |