blob: 3c0d6622966dc781846533d2332a2b3b16378e78 [file] [log] [blame]
From 3ffc80959f01f9fde548f1632694b9f950c2dd7c Mon Sep 17 00:00:00 2001
From: Christian Heimes <christian@python.org>
Date: Tue, 18 Sep 2018 15:13:09 +0200
Subject: [PATCH] [2.7] bpo-34623: Use XML_SetHashSalt in _elementtree
(GH-9146) (GH-9394)
The C accelerated _elementtree module now initializes hash randomization
salt from _Py_HashSecret instead of libexpat's default CPRNG.
Signed-off-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue34623.
(cherry picked from commit cb5778f00ce48631c7140f33ba242496aaf7102b)
Co-authored-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue34623
Upstream-Status: Backport
CVE: CVE-2018-14647
Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
Include/pyexpat.h | 4 +++-
Misc/NEWS.d/next/Security/2018-09-10-16-05-39.bpo-34623.Ua9jMv.rst | 2 ++
Modules/_elementtree.c | 5 +++++
Modules/pyexpat.c | 5 +++++
4 files changed, 15 insertions(+), 1 deletion(-)
create mode 100644 Misc/NEWS.d/next/Security/2018-09-10-16-05-39.bpo-34623.Ua9jMv.rst
diff --git a/Include/pyexpat.h b/Include/pyexpat.h
index 5340ef5..3fc5fa5 100644
--- a/Include/pyexpat.h
+++ b/Include/pyexpat.h
@@ -3,7 +3,7 @@
/* note: you must import expat.h before importing this module! */
-#define PyExpat_CAPI_MAGIC "pyexpat.expat_CAPI 1.0"
+#define PyExpat_CAPI_MAGIC "pyexpat.expat_CAPI 1.1"
#define PyExpat_CAPSULE_NAME "pyexpat.expat_CAPI"
struct PyExpat_CAPI
@@ -43,6 +43,8 @@ struct PyExpat_CAPI
XML_Parser parser, XML_UnknownEncodingHandler handler,
void *encodingHandlerData);
void (*SetUserData)(XML_Parser parser, void *userData);
+ /* might be none for expat < 2.1.0 */
+ int (*SetHashSalt)(XML_Parser parser, unsigned long hash_salt);
/* always add new stuff to the end! */
};
diff --git a/Misc/NEWS.d/next/Security/2018-09-10-16-05-39.bpo-34623.Ua9jMv.rst b/Misc/NEWS.d/next/Security/2018-09-10-16-05-39.bpo-34623.Ua9jMv.rst
new file mode 100644
index 0000000..31ad92e
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2018-09-10-16-05-39.bpo-34623.Ua9jMv.rst
@@ -0,0 +1,2 @@
+The C accelerated _elementtree module now initializes hash randomization
+salt from _Py_HashSecret instead of libexpat's default CSPRNG.
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index 1d316a1..a19cbf7 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -2574,6 +2574,11 @@ xmlparser(PyObject* self_, PyObject* args, PyObject* kw)
PyErr_NoMemory();
return NULL;
}
+ /* expat < 2.1.0 has no XML_SetHashSalt() */
+ if (EXPAT(SetHashSalt) != NULL) {
+ EXPAT(SetHashSalt)(self->parser,
+ (unsigned long)_Py_HashSecret.prefix);
+ }
ALLOC(sizeof(XMLParserObject), "create expatparser");
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 2b4d312..1f8c0d7 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -2042,6 +2042,11 @@ MODULE_INITFUNC(void)
capi.SetProcessingInstructionHandler = XML_SetProcessingInstructionHandler;
capi.SetUnknownEncodingHandler = XML_SetUnknownEncodingHandler;
capi.SetUserData = XML_SetUserData;
+#if XML_COMBINED_VERSION >= 20100
+ capi.SetHashSalt = XML_SetHashSalt;
+#else
+ capi.SetHashSalt = NULL;
+#endif
/* export using capsule */
capi_object = PyCapsule_New(&capi, PyExpat_CAPSULE_NAME, NULL);
--
2.7.4