execve(), spawnve(): add some extra sanity checking to env;

PyMapping_Check() doesn't guarantee that PyMapping_Size() won't raise
an exception, nor that keys and values are lists.

Also folded some long lines and did a little whitespace normalization.

Probably a 2.2 backport candidate.

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 61fc02d2b28c0c6acee75f172dc93a9b66e9a36b..b8475af17a0598584a2f4196db12e83343436cfc 100644 (file)
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2314,11 +2314,13 @@ posix_execve(PyObject *self, PyObject *args)
                getitem = PyTuple_GetItem;
        }
        else {
-               PyErr_SetString(PyExc_TypeError, "execve() arg 2 must be a tuple or list");
+               PyErr_SetString(PyExc_TypeError,
+                               "execve() arg 2 must be a tuple or list");
                goto fail_0;
        }
        if (!PyMapping_Check(env)) {
-               PyErr_SetString(PyExc_TypeError, "execve() arg 3 must be a mapping object");
+               PyErr_SetString(PyExc_TypeError,
+                               "execve() arg 3 must be a mapping object");
                goto fail_0;
        }
 
@@ -2347,6 +2349,8 @@ posix_execve(PyObject *self, PyObject *args)
        argvlist[argc] = NULL;
 
        i = PyMapping_Size(env);
+       if (i < 0)
+               goto fail_1;
        envlist = PyMem_NEW(char *, i + 1);
        if (envlist == NULL) {
                PyErr_NoMemory();
@@ -2357,6 +2361,11 @@ posix_execve(PyObject *self, PyObject *args)
        vals = PyMapping_Values(env);
        if (!keys || !vals)
                goto fail_2;
+       if (!PyList_Check(keys) || !PyList_Check(vals)) {
+               PyErr_SetString(PyExc_TypeError,
+                       "execve(): env.keys() or env.values() is not a list");
+               goto fail_2;
+       }
 
        for (pos = 0; pos < i; pos++) {
                char *p, *k, *v;
@@ -2367,8 +2376,14 @@ posix_execve(PyObject *self, PyObject *args)
                if (!key || !val)
                        goto fail_2;
 
-               if (!PyArg_Parse(key, "s;execve() arg 3 contains a non-string key", &k) ||
-                   !PyArg_Parse(val, "s;execve() arg 3 contains a non-string value", &v))
+               if (!PyArg_Parse(
+                           key,
+                           "s;execve() arg 3 contains a non-string key",
+                           &k) ||
+                   !PyArg_Parse(
+                           val,
+                           "s;execve() arg 3 contains a non-string value",
+                           &v))
                {
                        goto fail_2;
                }
@@ -2402,15 +2417,15 @@ posix_execve(PyObject *self, PyObject *args)
 
        (void) posix_error();
 
- fail_2:
+  fail_2:
        while (--envc >= 0)
                PyMem_DEL(envlist[envc]);
        PyMem_DEL(envlist);
- fail_1:
-       free_string_array(argvlist,lastarg);
+  fail_1:
+       free_string_array(argvlist, lastarg);
        Py_XDECREF(vals);
        Py_XDECREF(keys);
- fail_0:
+  fail_0:
        PyMem_Free(path);
        return NULL;
 }
@@ -2452,7 +2467,8 @@ posix_spawnv(PyObject *self, PyObject *args)
                getitem = PyTuple_GetItem;
        }
        else {
-               PyErr_SetString(PyExc_TypeError, "spawnv() arg 2 must be a tuple or list");
+               PyErr_SetString(PyExc_TypeError,
+                               "spawnv() arg 2 must be a tuple or list");
                PyMem_Free(path);
                return NULL;
        }
@@ -2467,8 +2483,9 @@ posix_spawnv(PyObject *self, PyObject *args)
                                 Py_FileSystemDefaultEncoding,
                                 &argvlist[i])) {
                        free_string_array(argvlist, i);
-                       PyErr_SetString(PyExc_TypeError,
-                                       "spawnv() arg 2 must contain only strings");
+                       PyErr_SetString(
+                               PyExc_TypeError,
+                               "spawnv() arg 2 must contain only strings");
                        PyMem_Free(path);
                        return NULL;
                }
@@ -2541,11 +2558,13 @@ posix_spawnve(PyObject *self, PyObject *args)
                getitem = PyTuple_GetItem;
        }
        else {
-               PyErr_SetString(PyExc_TypeError, "spawnve() arg 2 must be a tuple or list");
+               PyErr_SetString(PyExc_TypeError,
+                               "spawnve() arg 2 must be a tuple or list");
                goto fail_0;
        }
        if (!PyMapping_Check(env)) {
-               PyErr_SetString(PyExc_TypeError, "spawnve() arg 3 must be a mapping object");
+               PyErr_SetString(PyExc_TypeError,
+                               "spawnve() arg 3 must be a mapping object");
                goto fail_0;
        }
 
@@ -2556,7 +2575,7 @@ posix_spawnve(PyObject *self, PyObject *args)
        }
        for (i = 0; i < argc; i++) {
                if (!PyArg_Parse((*getitem)(argv, i),
-                                "et;spawnve() arg 2 must contain only strings",
+                            "et;spawnve() arg 2 must contain only strings",
                                 Py_FileSystemDefaultEncoding,
                                 &argvlist[i]))
                {
@@ -2568,6 +2587,8 @@ posix_spawnve(PyObject *self, PyObject *args)
        argvlist[argc] = NULL;
 
        i = PyMapping_Size(env);
+       if (i < 0)
+               goto fail_1;
        envlist = PyMem_NEW(char *, i + 1);
        if (envlist == NULL) {
                PyErr_NoMemory();
@@ -2578,6 +2599,11 @@ posix_spawnve(PyObject *self, PyObject *args)
        vals = PyMapping_Values(env);
        if (!keys || !vals)
                goto fail_2;
+       if (!PyList_Check(keys) || !PyList_Check(vals)) {
+               PyErr_SetString(PyExc_TypeError,
+                       "spawnve(): env.keys() or env.values() is not a list");
+               goto fail_2;
+       }
 
        for (pos = 0; pos < i; pos++) {
                char *p, *k, *v;
@@ -2588,8 +2614,14 @@ posix_spawnve(PyObject *self, PyObject *args)
                if (!key || !val)
                        goto fail_2;
 
-               if (!PyArg_Parse(key, "s;spawnve() arg 3 contains a non-string key", &k) ||
-                   !PyArg_Parse(val, "s;spawnve() arg 3 contains a non-string value", &v))
+               if (!PyArg_Parse(
+                           key,
+                           "s;spawnve() arg 3 contains a non-string key",
+                           &k) ||
+                   !PyArg_Parse(
+                           val,
+                           "s;spawnve() arg 3 contains a non-string value",
+                           &v))
                {
                        goto fail_2;
                }
@@ -2626,11 +2658,11 @@ posix_spawnve(PyObject *self, PyObject *args)
                res = Py_BuildValue("L", (LONG_LONG) spawnval);
 #endif
 
- fail_2:
+  fail_2:
        while (--envc >= 0)
                PyMem_DEL(envlist[envc]);
        PyMem_DEL(envlist);
- fail_1:
+  fail_1:
        free_string_array(argvlist, lastarg);
        Py_XDECREF(vals);
        Py_XDECREF(keys);