From 15e5b1bf0b6d53b8eed2e1c825f37efba64f317e Mon Sep 17 00:00:00 2001
From: Victor Stinner <victor.stinner@haypocalc.com>
Date: Sat, 3 Jul 2010 13:36:19 +0000
Subject: Issue #7673: Fix security vulnerability (CVE-2010-2089) in the
 audioop module, ensure that the input string length is a multiple of the
 frame size

---
 Lib/test/test_audioop.py |  33 +++++++++++
 Misc/NEWS                |   5 +-
 Modules/audioop.c        | 144 +++++++++++++++++++++++------------------------
 3 files changed, 108 insertions(+), 74 deletions(-)

diff --git a/Lib/test/test_audioop.py b/Lib/test/test_audioop.py
index 7bc2cd6..e03ceb5 100644
--- a/Lib/test/test_audioop.py
+++ b/Lib/test/test_audioop.py
@@ -20,6 +20,12 @@ def gendata4():
 
 data = [gendata1(), gendata2(), gendata4()]
 
+INVALID_DATA = [
+    ('abc', 0),
+    ('abc', 2),
+    ('abc', 4),
+]
+
 
 class TestAudioop(unittest.TestCase):
 
@@ -166,6 +172,33 @@ class TestAudioop(unittest.TestCase):
         self.assertRaises(audioop.error,
             audioop.findmax, ''.join( chr(x) for x in xrange(256)), -2392392)
 
+    def test_issue7673(self):
+        state = None
+        for data, size in INVALID_DATA:
+            size2 = size
+            self.assertRaises(audioop.error, audioop.getsample, data, size, 0)
+            self.assertRaises(audioop.error, audioop.max, data, size)
+            self.assertRaises(audioop.error, audioop.minmax, data, size)
+            self.assertRaises(audioop.error, audioop.avg, data, size)
+            self.assertRaises(audioop.error, audioop.rms, data, size)
+            self.assertRaises(audioop.error, audioop.avgpp, data, size)
+            self.assertRaises(audioop.error, audioop.maxpp, data, size)
+            self.assertRaises(audioop.error, audioop.cross, data, size)
+            self.assertRaises(audioop.error, audioop.mul, data, size, 1.0)
+            self.assertRaises(audioop.error, audioop.tomono, data, size, 0.5, 0.5)
+            self.assertRaises(audioop.error, audioop.tostereo, data, size, 0.5, 0.5)
+            self.assertRaises(audioop.error, audioop.add, data, data, size)
+            self.assertRaises(audioop.error, audioop.bias, data, size, 0)
+            self.assertRaises(audioop.error, audioop.reverse, data, size)
+            self.assertRaises(audioop.error, audioop.lin2lin, data, size, size2)
+            self.assertRaises(audioop.error, audioop.ratecv, data, size, 1, 1, 1, state)
+            self.assertRaises(audioop.error, audioop.lin2ulaw, data, size)
+            self.assertRaises(audioop.error, audioop.ulaw2lin, data, size)
+            self.assertRaises(audioop.error, audioop.lin2alaw, data, size)
+            self.assertRaises(audioop.error, audioop.alaw2lin, data, size)
+            self.assertRaises(audioop.error, audioop.lin2adpcm, data, size, state)
+            self.assertRaises(audioop.error, audioop.adpcm2lin, data, size, state)
+
 def test_main():
     run_unittest(TestAudioop)
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 1625c0c..ab9e071 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -17,6 +17,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #7673: Fix security vulnerability (CVE-2010-2089) in the audioop
+  module, ensure that the input string length is a multiple of the frame size
+
 - Issue #9075: In the ssl module, remove the setting of a ``debug`` flag
   on an OpenSSL structure.
 
@@ -51,7 +54,7 @@ Build
 Library
 -------
 
-- Issue #6589: cleanup asyncore.socket_map in case smtpd.SMTPServer constructor 
+- Issue #6589: cleanup asyncore.socket_map in case smtpd.SMTPServer constructor
   raises an exception.
 
 - Issue #8959: fix regression caused by using unmodified libffi
diff --git a/Modules/audioop.c b/Modules/audioop.c
index ba8f7ac..fb69ed3 100644
--- a/Modules/audioop.c
+++ b/Modules/audioop.c
@@ -295,6 +295,29 @@ static int stepsizeTable[89] = {
 
 static PyObject *AudioopError;
 
+static int
+audioop_check_size(int size)
+{
+    if (size != 1 && size != 2 && size != 4) {
+        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+        return 0;
+    }
+    else
+        return 1;
+}
+
+static int
+audioop_check_parameters(int len, int size)
+{
+    if (!audioop_check_size(size))
+        return 0;
+    if (len % size != 0) {
+        PyErr_SetString(AudioopError, "not a whole number of frames");
+        return 0;
+    }
+    return 1;
+}
+
 static PyObject *
 audioop_getsample(PyObject *self, PyObject *args)
 {
@@ -304,10 +327,8 @@ audioop_getsample(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#ii:getsample", &cp, &len, &size, &i) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     if ( i < 0 || i >= len/size ) {
         PyErr_SetString(AudioopError, "Index out of range");
         return 0;
@@ -328,10 +349,8 @@ audioop_max(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#i:max", &cp, &len, &size) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     for ( i=0; i<len; i+= size) {
         if ( size == 1 )      val = (int)*CHARP(cp, i);
         else if ( size == 2 ) val = (int)*SHORTP(cp, i);
@@ -352,10 +371,8 @@ audioop_minmax(PyObject *self, PyObject *args)
 
     if (!PyArg_ParseTuple(args, "s#i:minmax", &cp, &len, &size))
         return NULL;
-    if (size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+    if (!audioop_check_parameters(len, size))
         return NULL;
-    }
     for (i = 0; i < len; i += size) {
         if (size == 1) val = (int) *CHARP(cp, i);
         else if (size == 2) val = (int) *SHORTP(cp, i);
@@ -376,10 +393,8 @@ audioop_avg(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#i:avg", &cp, &len, &size) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     for ( i=0; i<len; i+= size) {
         if ( size == 1 )      val = (int)*CHARP(cp, i);
         else if ( size == 2 ) val = (int)*SHORTP(cp, i);
@@ -403,10 +418,8 @@ audioop_rms(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#i:rms", &cp, &len, &size) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     for ( i=0; i<len; i+= size) {
         if ( size == 1 )      val = (int)*CHARP(cp, i);
         else if ( size == 2 ) val = (int)*SHORTP(cp, i);
@@ -612,10 +625,8 @@ audioop_avgpp(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#i:avgpp", &cp, &len, &size) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     /* Compute first delta value ahead. Also automatically makes us
     ** skip the first extreme value
     */
@@ -669,10 +680,8 @@ audioop_maxpp(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#i:maxpp", &cp, &len, &size) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     /* Compute first delta value ahead. Also automatically makes us
     ** skip the first extreme value
     */
@@ -720,10 +729,8 @@ audioop_cross(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#i:cross", &cp, &len, &size) )
         return 0;
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
     ncross = -1;
     prevval = 17; /* Anything <> 0,1 */
     for ( i=0; i<len; i+= size) {
@@ -748,6 +755,8 @@ audioop_mul(PyObject *self, PyObject *args)
 
     if ( !PyArg_ParseTuple(args, "s#id:mul", &cp, &len, &size, &factor ) )
         return 0;
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     if ( size == 1 ) maxval = (double) 0x7f;
     else if ( size == 2 ) maxval = (double) 0x7fff;
@@ -790,6 +799,12 @@ audioop_tomono(PyObject *self, PyObject *args)
     if ( !PyArg_ParseTuple(args, "s#idd:tomono",
                            &cp, &len, &size, &fac1, &fac2 ) )
         return 0;
+    if (!audioop_check_parameters(len, size))
+        return NULL;
+    if (((len / size) & 1) != 0) {
+        PyErr_SetString(AudioopError, "not a whole number of frames");
+        return NULL;
+    }
 
     if ( size == 1 ) maxval = (double) 0x7f;
     else if ( size == 2 ) maxval = (double) 0x7fff;
@@ -835,6 +850,8 @@ audioop_tostereo(PyObject *self, PyObject *args)
     if ( !PyArg_ParseTuple(args, "s#idd:tostereo",
                            &cp, &len, &size, &fac1, &fac2 ) )
         return 0;
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     if ( size == 1 ) maxval = (double) 0x7f;
     else if ( size == 2 ) maxval = (double) 0x7fff;
@@ -893,7 +910,8 @@ audioop_add(PyObject *self, PyObject *args)
     if ( !PyArg_ParseTuple(args, "s#s#i:add",
                       &cp1, &len1, &cp2, &len2, &size ) )
         return 0;
-
+    if (!audioop_check_parameters(len1, size))
+        return NULL;
     if ( len1 != len2 ) {
         PyErr_SetString(AudioopError, "Lengths should be the same");
         return 0;
@@ -948,10 +966,8 @@ audioop_bias(PyObject *self, PyObject *args)
                       &cp, &len, &size , &bias) )
         return 0;
 
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     rv = PyString_FromStringAndSize(NULL, len);
     if ( rv == 0 )
@@ -984,10 +1000,8 @@ audioop_reverse(PyObject *self, PyObject *args)
                       &cp, &len, &size) )
         return 0;
 
-    if ( size != 1 && size != 2 && size != 4 ) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     rv = PyString_FromStringAndSize(NULL, len);
     if ( rv == 0 )
@@ -1021,11 +1035,10 @@ audioop_lin2lin(PyObject *self, PyObject *args)
                       &cp, &len, &size, &size2) )
         return 0;
 
-    if ( (size != 1 && size != 2 && size != 4) ||
-         (size2 != 1 && size2 != 2 && size2 != 4)) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
+    if (!audioop_check_size(size2))
+        return NULL;
 
     if (len/size > INT_MAX/size2) {
         PyErr_SetString(PyExc_MemoryError,
@@ -1075,10 +1088,8 @@ audioop_ratecv(PyObject *self, PyObject *args)
                           &nchannels, &inrate, &outrate, &state,
                           &weightA, &weightB))
         return NULL;
-    if (size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+    if (!audioop_check_size(size))
         return NULL;
-    }
     if (nchannels < 1) {
         PyErr_SetString(AudioopError, "# of channels should be >= 1");
         return NULL;
@@ -1255,10 +1266,8 @@ audioop_lin2ulaw(PyObject *self, PyObject *args)
                            &cp, &len, &size) )
         return 0 ;
 
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     rv = PyString_FromStringAndSize(NULL, len/size);
     if ( rv == 0 )
@@ -1289,10 +1298,8 @@ audioop_ulaw2lin(PyObject *self, PyObject *args)
                            &cp, &len, &size) )
         return 0;
 
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     if (len > INT_MAX/size) {
         PyErr_SetString(PyExc_MemoryError,
@@ -1328,10 +1335,8 @@ audioop_lin2alaw(PyObject *self, PyObject *args)
                            &cp, &len, &size) )
         return 0;
 
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     rv = PyString_FromStringAndSize(NULL, len/size);
     if ( rv == 0 )
@@ -1362,10 +1367,8 @@ audioop_alaw2lin(PyObject *self, PyObject *args)
                            &cp, &len, &size) )
         return 0;
 
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     if (len > INT_MAX/size) {
         PyErr_SetString(PyExc_MemoryError,
@@ -1402,11 +1405,8 @@ audioop_lin2adpcm(PyObject *self, PyObject *args)
                            &cp, &len, &size, &state) )
         return 0;
 
-
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     str = PyString_FromStringAndSize(NULL, len/(size*2));
     if ( str == 0 )
@@ -1509,10 +1509,8 @@ audioop_adpcm2lin(PyObject *self, PyObject *args)
                            &cp, &len, &size, &state) )
         return 0;
 
-    if ( size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
-        return 0;
-    }
+    if (!audioop_check_parameters(len, size))
+        return NULL;
 
     /* Decode state, should have (value, step) */
     if ( state == Py_None ) {
-- 
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