From 9ec213bf67afbdfdbe25802ec86487bb22aeb2e4 Mon Sep 17 00:00:00 2001 From: Daniel BORNAZ Date: Thu, 24 Jul 2014 15:51:44 +0200 Subject: python: fix _json module arbitrary process memory read vulnerability http://bugs.python.org/issue21529 Python 2 and 3 are susceptible to arbitrary process memory reading by a user or adversary due to a bug in the _json module caused by insufficient bounds checking. The sole prerequisites of this attack are that the attacker is able to control or influence the two parameters of the default scanstring function: the string to be decoded and the index. The bug is caused by allowing the user to supply a negative index value. The index value is then used directly as an index to an array in the C code; internally the address of the array and its index are added to each other in order to yield the address of the value that is desired. However, by supplying a negative index value and adding this to the address of the array, the processor's register value wraps around and the calculated value will point to a position in memory which isn't within the bounds of the supplied string, causing the function to access other parts of the process memory. Signed-off-by: Benjamin Peterson Applied to python-native recipe in order to fix the above mentioned vulnerability. Upstream-Status: Submitted Signed-off-by: Daniel BORNAZ Signed-off-by: Saul Wold Signed-off-by: Richard Purdie --- .../recipes-devtools/python/python-native_2.7.3.bb | 1 + .../python/python/json-flaw-fix.patch | 27 ++++++++++++++++++++++ meta/recipes-devtools/python/python_2.7.3.bb | 1 + 3 files changed, 29 insertions(+) create mode 100644 meta/recipes-devtools/python/python/json-flaw-fix.patch diff --git a/meta/recipes-devtools/python/python-native_2.7.3.bb b/meta/recipes-devtools/python/python-native_2.7.3.bb index 0571d3a488..827654dfa2 100644 --- a/meta/recipes-devtools/python/python-native_2.7.3.bb +++ b/meta/recipes-devtools/python/python-native_2.7.3.bb @@ -19,6 +19,7 @@ SRC_URI += "\ file://parallel-makeinst-create-bindir.patch \ file://python-fix-build-error-with-Readline-6.3.patch \ file://gcc-4.8-fix-configure-Wformat.patch \ + file://json-flaw-fix.patch \ " S = "${WORKDIR}/Python-${PV}" diff --git a/meta/recipes-devtools/python/python/json-flaw-fix.patch b/meta/recipes-devtools/python/python/json-flaw-fix.patch new file mode 100644 index 0000000000..e9a6cca017 --- /dev/null +++ b/meta/recipes-devtools/python/python/json-flaw-fix.patch @@ -0,0 +1,27 @@ + +python: fix _json module arbitrary process memory read vulnerability + +Upstream-Status: submitted + +Signed-off-by: Daniel BORNAZ + +--- a/Modules/_json.c 2014-07-15 15:37:17.151046356 +0200 ++++ b/Modules/_json.c 2014-07-15 15:38:37.335605042 +0200 +@@ -1491,7 +1491,7 @@ scan_once_str(PyScannerObject *s, PyObje + PyObject *res; + char *str = PyString_AS_STRING(pystr); + Py_ssize_t length = PyString_GET_SIZE(pystr); +- if (idx >= length) { ++ if ( idx < 0 || idx >= length) { + PyErr_SetNone(PyExc_StopIteration); + return NULL; + } +@@ -1578,7 +1578,7 @@ scan_once_unicode(PyScannerObject *s, Py + PyObject *res; + Py_UNICODE *str = PyUnicode_AS_UNICODE(pystr); + Py_ssize_t length = PyUnicode_GET_SIZE(pystr); +- if (idx >= length) { ++ if ( idx < 0 || idx >= length) { + PyErr_SetNone(PyExc_StopIteration); + return NULL; + } diff --git a/meta/recipes-devtools/python/python_2.7.3.bb b/meta/recipes-devtools/python/python_2.7.3.bb index 0d641720f1..5be9073829 100644 --- a/meta/recipes-devtools/python/python_2.7.3.bb +++ b/meta/recipes-devtools/python/python_2.7.3.bb @@ -36,6 +36,7 @@ SRC_URI += "\ file://python-2.7.3-CVE-2013-1752-smtplib-fix.patch \ file://python-fix-build-error-with-Readline-6.3.patch \ file://python-2.7.3-CVE-2014-1912.patch \ + file://json-flaw-fix.patch \ " S = "${WORKDIR}/Python-${PV}" -- cgit 1.2.3-korg