From 86430a8e545cc2e2d40be0e25875f47e43b25443 Mon Sep 17 00:00:00 2001 From: David King Date: Thu, 13 May 2021 15:03:52 +0100 Subject: [PATCH] Fix CVE-2021-3518 (#1957029) Resolves: #1957029 Resolves: CVE-2021-3518 --- libxml2-2.9.10-CVE-2021-3518.patch | 247 +++++++++++++++++++++++++++++ libxml2.spec | 3 + 2 files changed, 250 insertions(+) create mode 100644 libxml2-2.9.10-CVE-2021-3518.patch diff --git a/libxml2-2.9.10-CVE-2021-3518.patch b/libxml2-2.9.10-CVE-2021-3518.patch new file mode 100644 index 0000000..e5861c2 --- /dev/null +++ b/libxml2-2.9.10-CVE-2021-3518.patch @@ -0,0 +1,247 @@ +From 752e5f71d7cea2ca5a7e7c0b8f72ed04ce654be4 Mon Sep 17 00:00:00 2001 +From: Nick Wellnhofer +Date: Wed, 10 Jun 2020 16:34:52 +0200 +Subject: [PATCH 1/2] Don't recurse into xi:include children in + xmlXIncludeDoProcess + +Otherwise, nested xi:include nodes might result in a use-after-free +if XML_PARSE_NOXINCNODE is specified. + +Found with libFuzzer and ASan. +--- + result/XInclude/fallback3.xml | 8 ++++++++ + result/XInclude/fallback3.xml.err | 0 + result/XInclude/fallback3.xml.rdr | 25 +++++++++++++++++++++++++ + result/XInclude/fallback4.xml | 10 ++++++++++ + result/XInclude/fallback4.xml.err | 0 + result/XInclude/fallback4.xml.rdr | 29 +++++++++++++++++++++++++++++ + test/XInclude/docs/fallback3.xml | 9 +++++++++ + test/XInclude/docs/fallback4.xml | 7 +++++++ + xinclude.c | 24 ++++++++++-------------- + 9 files changed, 98 insertions(+), 14 deletions(-) + create mode 100644 result/XInclude/fallback3.xml + create mode 100644 result/XInclude/fallback3.xml.err + create mode 100644 result/XInclude/fallback3.xml.rdr + create mode 100644 result/XInclude/fallback4.xml + create mode 100644 result/XInclude/fallback4.xml.err + create mode 100644 result/XInclude/fallback4.xml.rdr + create mode 100644 test/XInclude/docs/fallback3.xml + create mode 100644 test/XInclude/docs/fallback4.xml + +diff --git a/result/XInclude/fallback3.xml b/result/XInclude/fallback3.xml +new file mode 100644 +index 00000000..b4235514 +--- /dev/null ++++ b/result/XInclude/fallback3.xml +@@ -0,0 +1,8 @@ ++ ++ ++ ++

something

++

really

++

simple

++ ++ +diff --git a/result/XInclude/fallback3.xml.err b/result/XInclude/fallback3.xml.err +new file mode 100644 +index 00000000..e69de29b +diff --git a/result/XInclude/fallback3.xml.rdr b/result/XInclude/fallback3.xml.rdr +new file mode 100644 +index 00000000..aa2f1374 +--- /dev/null ++++ b/result/XInclude/fallback3.xml.rdr +@@ -0,0 +1,25 @@ ++0 1 a 0 0 ++1 14 #text 0 1 ++ ++1 1 doc 0 0 ++2 14 #text 0 1 ++ ++2 1 p 0 0 ++3 3 #text 0 1 something ++2 15 p 0 0 ++2 14 #text 0 1 ++ ++2 1 p 0 0 ++3 3 #text 0 1 really ++2 15 p 0 0 ++2 14 #text 0 1 ++ ++2 1 p 0 0 ++3 3 #text 0 1 simple ++2 15 p 0 0 ++2 14 #text 0 1 ++ ++1 15 doc 0 0 ++1 14 #text 0 1 ++ ++0 15 a 0 0 +diff --git a/result/XInclude/fallback4.xml b/result/XInclude/fallback4.xml +new file mode 100644 +index 00000000..9883fd54 +--- /dev/null ++++ b/result/XInclude/fallback4.xml +@@ -0,0 +1,10 @@ ++ ++ ++ ++ ++

something

++

really

++

simple

++ ++ ++ +diff --git a/result/XInclude/fallback4.xml.err b/result/XInclude/fallback4.xml.err +new file mode 100644 +index 00000000..e69de29b +diff --git a/result/XInclude/fallback4.xml.rdr b/result/XInclude/fallback4.xml.rdr +new file mode 100644 +index 00000000..628b9513 +--- /dev/null ++++ b/result/XInclude/fallback4.xml.rdr +@@ -0,0 +1,29 @@ ++0 1 a 0 0 ++1 14 #text 0 1 ++ ++1 14 #text 0 1 ++ ++1 1 doc 0 0 ++2 14 #text 0 1 ++ ++2 1 p 0 0 ++3 3 #text 0 1 something ++2 15 p 0 0 ++2 14 #text 0 1 ++ ++2 1 p 0 0 ++3 3 #text 0 1 really ++2 15 p 0 0 ++2 14 #text 0 1 ++ ++2 1 p 0 0 ++3 3 #text 0 1 simple ++2 15 p 0 0 ++2 14 #text 0 1 ++ ++1 15 doc 0 0 ++1 14 #text 0 1 ++ ++1 14 #text 0 1 ++ ++0 15 a 0 0 +diff --git a/test/XInclude/docs/fallback3.xml b/test/XInclude/docs/fallback3.xml +new file mode 100644 +index 00000000..0c8b6c9e +--- /dev/null ++++ b/test/XInclude/docs/fallback3.xml +@@ -0,0 +1,9 @@ ++ ++ ++ ++ ++ There is no c.xml ... ++ ++ ++ ++ +diff --git a/test/XInclude/docs/fallback4.xml b/test/XInclude/docs/fallback4.xml +new file mode 100644 +index 00000000..b500a635 +--- /dev/null ++++ b/test/XInclude/docs/fallback4.xml +@@ -0,0 +1,7 @@ ++ ++ ++ ++ ++ ++ ++ +diff --git a/xinclude.c b/xinclude.c +index ba850fa5..f260c1a7 100644 +--- a/xinclude.c ++++ b/xinclude.c +@@ -2392,21 +2392,19 @@ xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree) { + * First phase: lookup the elements in the document + */ + cur = tree; +- if (xmlXIncludeTestNode(ctxt, cur) == 1) +- xmlXIncludePreProcessNode(ctxt, cur); + while ((cur != NULL) && (cur != tree->parent)) { + /* TODO: need to work on entities -> stack */ +- if ((cur->children != NULL) && +- (cur->children->type != XML_ENTITY_DECL) && +- (cur->children->type != XML_XINCLUDE_START) && +- (cur->children->type != XML_XINCLUDE_END)) { +- cur = cur->children; +- if (xmlXIncludeTestNode(ctxt, cur)) +- xmlXIncludePreProcessNode(ctxt, cur); +- } else if (cur->next != NULL) { ++ if (xmlXIncludeTestNode(ctxt, cur) == 1) { ++ xmlXIncludePreProcessNode(ctxt, cur); ++ } else if ((cur->children != NULL) && ++ (cur->children->type != XML_ENTITY_DECL) && ++ (cur->children->type != XML_XINCLUDE_START) && ++ (cur->children->type != XML_XINCLUDE_END)) { ++ cur = cur->children; ++ continue; ++ } ++ if (cur->next != NULL) { + cur = cur->next; +- if (xmlXIncludeTestNode(ctxt, cur)) +- xmlXIncludePreProcessNode(ctxt, cur); + } else { + if (cur == tree) + break; +@@ -2416,8 +2414,6 @@ xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree) { + break; /* do */ + if (cur->next != NULL) { + cur = cur->next; +- if (xmlXIncludeTestNode(ctxt, cur)) +- xmlXIncludePreProcessNode(ctxt, cur); + break; /* do */ + } + } while (cur != NULL); +-- +2.31.1 + + +From 49cc4182543dba73216add4021994a81678763bd Mon Sep 17 00:00:00 2001 +From: Nick Wellnhofer +Date: Thu, 22 Apr 2021 19:26:28 +0200 +Subject: [PATCH 2/2] Fix user-after-free with `xmllint --xinclude --dropdtd` + +The --dropdtd option can leave dangling pointers in entity reference +nodes. Make sure to skip these nodes when processing XIncludes. + +This also avoids scanning entity declarations and even modifying +them inadvertently during XInclude processing. + +Move from a block list to an allow list approach to avoid descending +into other node types that can't contain elements. + +Fixes #237. +--- + xinclude.c | 5 ++--- + 1 file changed, 2 insertions(+), 3 deletions(-) + +diff --git a/xinclude.c b/xinclude.c +index f260c1a7..d7648529 100644 +--- a/xinclude.c ++++ b/xinclude.c +@@ -2397,9 +2397,8 @@ xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree) { + if (xmlXIncludeTestNode(ctxt, cur) == 1) { + xmlXIncludePreProcessNode(ctxt, cur); + } else if ((cur->children != NULL) && +- (cur->children->type != XML_ENTITY_DECL) && +- (cur->children->type != XML_XINCLUDE_START) && +- (cur->children->type != XML_XINCLUDE_END)) { ++ ((cur->type == XML_DOCUMENT_NODE) || ++ (cur->type == XML_ELEMENT_NODE))) { + cur = cur->children; + continue; + } +-- +2.31.1 + diff --git a/libxml2.spec b/libxml2.spec index 5fbfc21..94eb986 100644 --- a/libxml2.spec +++ b/libxml2.spec @@ -26,6 +26,8 @@ Patch8: python-py_ssize_t.patch Patch9: libxml2-2.9.10-CVE-2021-3516.patch # https://bugzilla.redhat.com/show_bug.cgi?id=1957002 Patch10: libxml2-2.9.10-CVE-2021-3517.patch +# https://bugzilla.redhat.com/show_bug.cgi?id=1957029 +Patch11: libxml2-2.9.10-CVE-2021-3518.patch BuildRequires: gcc BuildRequires: make @@ -160,6 +162,7 @@ gzip -9 -c doc/libxml2-api.xml > doc/libxml2-api.xml.gz * Thu May 13 2021 David King - 2.9.10-12 - Fix CVE-2021-3516 (#1956969) - Fix CVE-2021-3517 (#1957002) +- Fix CVE-2021-3518 (#1957029) * Fri Apr 16 2021 Mohan Boddu - 2.9.10-11 - Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937