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Merge in release25-maint r60793:

Browse source 
Added checks for integer overflows, contributed by Google. Some are
 only available if asserts are left in the code, in cases where they
 can't be triggered from Python code.
This commit is contained in:
Gregory P. Smith 2008-06-11 07:41:16 +00:00
parent 73baefd7fc
commit 9d53457e59
24 changed files with 438 additions and 54 deletions
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60
Python/bltinmodule.c
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@ -2792,11 +2792,43 @@ filterstring(PyObject *func, PyObject *strobj)
PyString_AS_STRING(item)[0];
} else {
/* do we need more space? */
Py_ssize_t need = j + reslen + len-i-1;
Py_ssize_t need = j;
/* calculate space requirements while checking for overflow */
if (need > PY_SSIZE_T_MAX - reslen) {
Py_DECREF(item);
goto Fail_1;
}
need += reslen;
if (need > PY_SSIZE_T_MAX - len) {
Py_DECREF(item);
goto Fail_1;
}
need += len;
if (need <= i) {
Py_DECREF(item);
goto Fail_1;
}
need = need - i - 1;
assert(need >= 0);
assert(outlen >= 0);
if (need > outlen) {
/* overallocate, to avoid reallocations */
if (need<2*outlen)
if (outlen > PY_SSIZE_T_MAX / 2) {
Py_DECREF(item);
return NULL;
}
if (need<2*outlen) {
need = 2*outlen;
}
if (_PyString_Resize(&result, need)) {
Py_DECREF(item);
return NULL;
@ -2888,11 +2920,31 @@ filterunicode(PyObject *func, PyObject *strobj)
else {
/* do we need more space? */
Py_ssize_t need = j + reslen + len - i - 1;
/* check that didnt overflow */
if ((j > PY_SSIZE_T_MAX - reslen) ||
((j + reslen) > PY_SSIZE_T_MAX - len) ||
((j + reslen + len) < i) ||
((j + reslen + len - i) <= 0)) {
Py_DECREF(item);
return NULL;
}
assert(need >= 0);
assert(outlen >= 0);
if (need > outlen) {
/* overallocate,
to avoid reallocations */
if (need < 2 * outlen)
need = 2 * outlen;
if (need < 2 * outlen) {
if (outlen > PY_SSIZE_T_MAX / 2) {
Py_DECREF(item);
return NULL;
} else {
need = 2 * outlen;
}
}
if (PyUnicode_Resize(
&result, need) < 0) {
Py_DECREF(item);