untrusted comment: verify with openbsd-69-base.pub
RWQQsAemppS46NMFWMtYm0jcmdfbA+kr2P3RPiIIvb1v51R1NTy1og5p6TszxVMCZnzgAweM/ifjATY7OzR9C2+l8FxwqpelyAM=
OpenBSD 6.9 errata 026, January 19, 2022:
Fix 8 security issues in libexpat, all related to fixed-size integer
math (integer overflow and invalid shifts) near memory allocation.
Apply by doing:
signify -Vep /etc/signify/openbsd-69-base.pub -x 026_expat.patch.sig \
-m - | (cd /usr/src && patch -p0)
And then rebuild and install libexpat:
cd /usr/src/lib/libexpat
make obj
make
make install
Index: lib/libexpat/Changes
===================================================================
RCS file: /cvs/src/lib/libexpat/Changes,v
diff -u -p -u -p -r1.15 Changes
--- lib/libexpat/Changes 29 Dec 2020 16:59:42 -0000 1.15
+++ lib/libexpat/Changes 17 Jan 2022 12:56:38 -0000
@@ -2,6 +2,34 @@ NOTE: We are looking for help with a few
https://github.com/libexpat/libexpat/labels/help%20wanted
If you can help, please get in touch. Thanks!
+ Security fixes:
+ #531 #534 CVE-2021-45960 -- Fix issues with left shifts by >=29 places
+ resulting in
+ a) realloc acting as free
+ b) realloc allocating too few bytes
+ c) undefined behavior
+ depending on architecture and precise value
+ for XML documents with >=2^27+1 prefixed attributes
+ on a single XML tag a la
+ ""
+ where XML_ParserCreateNS is used to create the parser
+ (which needs argument "-n" when running xmlwf).
+ Impact is denial of service, or more.
+ #532 #538 CVE-2021-46143 (ZDI-CAN-16157) -- Fix integer overflow
+ on variable m_groupSize in function doProlog leading
+ to realloc acting as free.
+ Impact is denial of service or more.
+ #539 CVE-2022-22822 to CVE-2022-22827 -- Prevent integer overflows
+ near memory allocation at multiple places. Mitre assigned
+ a dedicated CVE for each involved internal C function:
+ - CVE-2022-22822 for function addBinding
+ - CVE-2022-22823 for function build_model
+ - CVE-2022-22824 for function defineAttribute
+ - CVE-2022-22825 for function lookup
+ - CVE-2022-22826 for function nextScaffoldPart
+ - CVE-2022-22827 for function storeAtts
+ Impact is denial of service or more.
+
Release 2.2.10 Sat October 3 2020
Bug fixes:
#390 #395 #398 Fix undefined behavior during parsing caused by
Index: lib/libexpat/lib/xmlparse.c
===================================================================
RCS file: /cvs/src/lib/libexpat/lib/xmlparse.c,v
diff -u -p -u -p -r1.26 xmlparse.c
--- lib/libexpat/lib/xmlparse.c 29 Dec 2020 16:59:42 -0000 1.26
+++ lib/libexpat/lib/xmlparse.c 17 Jan 2022 12:56:39 -0000
@@ -8,6 +8,7 @@
Copyright (c) 1997-2000 Thai Open Source Software Center Ltd
Copyright (c) 2000-2017 Expat development team
+ Copyright (c) 2016-2022 Sebastian Pipping
Licensed under the MIT license:
Permission is hereby granted, free of charge, to any person obtaining
@@ -2891,13 +2892,38 @@ storeAtts(XML_Parser parser, const ENCOD
/* get the attributes from the tokenizer */
n = XmlGetAttributes(enc, attStr, parser->m_attsSize, parser->m_atts);
+
+ /* Detect and prevent integer overflow */
+ if (n > INT_MAX - nDefaultAtts) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
if (n + nDefaultAtts > parser->m_attsSize) {
int oldAttsSize = parser->m_attsSize;
ATTRIBUTE *temp;
#ifdef XML_ATTR_INFO
XML_AttrInfo *temp2;
#endif
+
+ /* Detect and prevent integer overflow */
+ if ((nDefaultAtts > INT_MAX - INIT_ATTS_SIZE)
+ || (n > INT_MAX - (nDefaultAtts + INIT_ATTS_SIZE))) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
parser->m_attsSize = n + nDefaultAtts + INIT_ATTS_SIZE;
+
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if ((unsigned)parser->m_attsSize > (size_t)(-1) / sizeof(ATTRIBUTE)) {
+ parser->m_attsSize = oldAttsSize;
+ return XML_ERROR_NO_MEMORY;
+ }
+#endif
+
temp = (ATTRIBUTE *)REALLOC(parser, (void *)parser->m_atts,
parser->m_attsSize * sizeof(ATTRIBUTE));
if (temp == NULL) {
@@ -2906,6 +2932,17 @@ storeAtts(XML_Parser parser, const ENCOD
}
parser->m_atts = temp;
#ifdef XML_ATTR_INFO
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+# if UINT_MAX >= SIZE_MAX
+ if ((unsigned)parser->m_attsSize > (size_t)(-1) / sizeof(XML_AttrInfo)) {
+ parser->m_attsSize = oldAttsSize;
+ return XML_ERROR_NO_MEMORY;
+ }
+# endif
+
temp2 = (XML_AttrInfo *)REALLOC(parser, (void *)parser->m_attInfo,
parser->m_attsSize * sizeof(XML_AttrInfo));
if (temp2 == NULL) {
@@ -3044,7 +3081,13 @@ storeAtts(XML_Parser parser, const ENCOD
if (nPrefixes) {
int j; /* hash table index */
unsigned long version = parser->m_nsAttsVersion;
- int nsAttsSize = (int)1 << parser->m_nsAttsPower;
+
+ /* Detect and prevent invalid shift */
+ if (parser->m_nsAttsPower >= sizeof(unsigned int) * 8 /* bits per byte */) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
+ unsigned int nsAttsSize = 1u << parser->m_nsAttsPower;
unsigned char oldNsAttsPower = parser->m_nsAttsPower;
/* size of hash table must be at least 2 * (# of prefixed attributes) */
if ((nPrefixes << 1)
@@ -3055,7 +3098,28 @@ storeAtts(XML_Parser parser, const ENCOD
;
if (parser->m_nsAttsPower < 3)
parser->m_nsAttsPower = 3;
- nsAttsSize = (int)1 << parser->m_nsAttsPower;
+
+ /* Detect and prevent invalid shift */
+ if (parser->m_nsAttsPower >= sizeof(nsAttsSize) * 8 /* bits per byte */) {
+ /* Restore actual size of memory in m_nsAtts */
+ parser->m_nsAttsPower = oldNsAttsPower;
+ return XML_ERROR_NO_MEMORY;
+ }
+
+ nsAttsSize = 1u << parser->m_nsAttsPower;
+
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if (nsAttsSize > (size_t)(-1) / sizeof(NS_ATT)) {
+ /* Restore actual size of memory in m_nsAtts */
+ parser->m_nsAttsPower = oldNsAttsPower;
+ return XML_ERROR_NO_MEMORY;
+ }
+#endif
+
temp = (NS_ATT *)REALLOC(parser, parser->m_nsAtts,
nsAttsSize * sizeof(NS_ATT));
if (! temp) {
@@ -3213,9 +3277,31 @@ storeAtts(XML_Parser parser, const ENCOD
tagNamePtr->prefixLen = prefixLen;
for (i = 0; localPart[i++];)
; /* i includes null terminator */
+
+ /* Detect and prevent integer overflow */
+ if (binding->uriLen > INT_MAX - prefixLen
+ || i > INT_MAX - (binding->uriLen + prefixLen)) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
n = i + binding->uriLen + prefixLen;
if (n > binding->uriAlloc) {
TAG *p;
+
+ /* Detect and prevent integer overflow */
+ if (n > INT_MAX - EXPAND_SPARE) {
+ return XML_ERROR_NO_MEMORY;
+ }
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if ((unsigned)(n + EXPAND_SPARE) > (size_t)(-1) / sizeof(XML_Char)) {
+ return XML_ERROR_NO_MEMORY;
+ }
+#endif
+
uri = (XML_Char *)MALLOC(parser, (n + EXPAND_SPARE) * sizeof(XML_Char));
if (! uri)
return XML_ERROR_NO_MEMORY;
@@ -3311,6 +3397,21 @@ addBinding(XML_Parser parser, PREFIX *pr
if (parser->m_freeBindingList) {
b = parser->m_freeBindingList;
if (len > b->uriAlloc) {
+ /* Detect and prevent integer overflow */
+ if (len > INT_MAX - EXPAND_SPARE) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if ((unsigned)(len + EXPAND_SPARE) > (size_t)(-1) / sizeof(XML_Char)) {
+ return XML_ERROR_NO_MEMORY;
+ }
+#endif
+
XML_Char *temp = (XML_Char *)REALLOC(
parser, b->uri, sizeof(XML_Char) * (len + EXPAND_SPARE));
if (temp == NULL)
@@ -3323,6 +3424,21 @@ addBinding(XML_Parser parser, PREFIX *pr
b = (BINDING *)MALLOC(parser, sizeof(BINDING));
if (! b)
return XML_ERROR_NO_MEMORY;
+
+ /* Detect and prevent integer overflow */
+ if (len > INT_MAX - EXPAND_SPARE) {
+ return XML_ERROR_NO_MEMORY;
+ }
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if ((unsigned)(len + EXPAND_SPARE) > (size_t)(-1) / sizeof(XML_Char)) {
+ return XML_ERROR_NO_MEMORY;
+ }
+#endif
+
b->uri
= (XML_Char *)MALLOC(parser, sizeof(XML_Char) * (len + EXPAND_SPARE));
if (! b->uri) {
@@ -4580,6 +4696,11 @@ doProlog(XML_Parser parser, const ENCODI
if (parser->m_prologState.level >= parser->m_groupSize) {
if (parser->m_groupSize) {
{
+ /* Detect and prevent integer overflow */
+ if (parser->m_groupSize > (unsigned int)(-1) / 2u) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
char *const new_connector = (char *)REALLOC(
parser, parser->m_groupConnector, parser->m_groupSize *= 2);
if (new_connector == NULL) {
@@ -4590,6 +4711,16 @@ doProlog(XML_Parser parser, const ENCODI
}
if (dtd->scaffIndex) {
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if (parser->m_groupSize > (size_t)(-1) / sizeof(int)) {
+ return XML_ERROR_NO_MEMORY;
+ }
+#endif
+
int *const new_scaff_index = (int *)REALLOC(
parser, dtd->scaffIndex, parser->m_groupSize * sizeof(int));
if (new_scaff_index == NULL)
@@ -5588,7 +5719,24 @@ defineAttribute(ELEMENT_TYPE *type, ATTR
}
} else {
DEFAULT_ATTRIBUTE *temp;
+
+ /* Detect and prevent integer overflow */
+ if (type->allocDefaultAtts > INT_MAX / 2) {
+ return 0;
+ }
+
int count = type->allocDefaultAtts * 2;
+
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if ((unsigned)count > (size_t)(-1) / sizeof(DEFAULT_ATTRIBUTE)) {
+ return 0;
+ }
+#endif
+
temp = (DEFAULT_ATTRIBUTE *)REALLOC(parser, type->defaultAtts,
(count * sizeof(DEFAULT_ATTRIBUTE)));
if (temp == NULL)
@@ -6239,8 +6387,20 @@ lookup(XML_Parser parser, HASH_TABLE *ta
/* check for overflow (table is half full) */
if (table->used >> (table->power - 1)) {
unsigned char newPower = table->power + 1;
+
+ /* Detect and prevent invalid shift */
+ if (newPower >= sizeof(unsigned long) * 8 /* bits per byte */) {
+ return NULL;
+ }
+
size_t newSize = (size_t)1 << newPower;
unsigned long newMask = (unsigned long)newSize - 1;
+
+ /* Detect and prevent integer overflow */
+ if (newSize > (size_t)(-1) / sizeof(NAMED *)) {
+ return NULL;
+ }
+
size_t tsize = newSize * sizeof(NAMED *);
NAMED **newV = (NAMED **)table->mem->malloc_fcn(tsize);
if (! newV)
@@ -6590,6 +6750,20 @@ nextScaffoldPart(XML_Parser parser) {
if (dtd->scaffCount >= dtd->scaffSize) {
CONTENT_SCAFFOLD *temp;
if (dtd->scaffold) {
+ /* Detect and prevent integer overflow */
+ if (dtd->scaffSize > UINT_MAX / 2u) {
+ return -1;
+ }
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if (dtd->scaffSize > (size_t)(-1) / 2u / sizeof(CONTENT_SCAFFOLD)) {
+ return -1;
+ }
+#endif
+
temp = (CONTENT_SCAFFOLD *)REALLOC(
parser, dtd->scaffold, dtd->scaffSize * 2 * sizeof(CONTENT_SCAFFOLD));
if (temp == NULL)
@@ -6659,8 +6833,26 @@ build_model(XML_Parser parser) {
XML_Content *ret;
XML_Content *cpos;
XML_Char *str;
- int allocsize = (dtd->scaffCount * sizeof(XML_Content)
- + (dtd->contentStringLen * sizeof(XML_Char)));
+
+ /* Detect and prevent integer overflow.
+ * The preprocessor guard addresses the "always false" warning
+ * from -Wtype-limits on platforms where
+ * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+ if (dtd->scaffCount > (size_t)(-1) / sizeof(XML_Content)) {
+ return NULL;
+ }
+ if (dtd->contentStringLen > (size_t)(-1) / sizeof(XML_Char)) {
+ return NULL;
+ }
+#endif
+ if (dtd->scaffCount * sizeof(XML_Content)
+ > (size_t)(-1) - dtd->contentStringLen * sizeof(XML_Char)) {
+ return NULL;
+ }
+
+ const size_t allocsize = (dtd->scaffCount * sizeof(XML_Content)
+ + (dtd->contentStringLen * sizeof(XML_Char)));
ret = (XML_Content *)MALLOC(parser, allocsize);
if (! ret)