Issue #18137: Detect integer overflow on precision in float.__format__()
and complex.__format__().
diff --git a/Lib/test/test_format.py b/Lib/test/test_format.py
index dd30efa..0ad8b02 100644
--- a/Lib/test/test_format.py
+++ b/Lib/test/test_format.py
@@ -302,6 +302,23 @@
def test_main():
test_support.run_unittest(FormatTest)
+ def test_precision(self):
+ INT_MAX = 2147483647
+
+ f = 1.2
+ self.assertEqual(format(f, ".0f"), "1")
+ self.assertEqual(format(f, ".3f"), "1.200")
+ with self.assertRaises(ValueError) as cm:
+ format(f, ".%sf" % (INT_MAX + 1))
+ self.assertEqual(str(cm.exception), "precision too big")
+
+ c = complex(f)
+ self.assertEqual(format(f, ".0f"), "1")
+ self.assertEqual(format(f, ".3f"), "1.200")
+ with self.assertRaises(ValueError) as cm:
+ format(f, ".%sf" % (INT_MAX + 1))
+ self.assertEqual(str(cm.exception), "precision too big")
+
if __name__ == "__main__":
unittest.main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 9418183..b455366 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -9,6 +9,9 @@
Core and Builtins
-----------------
+- Issue #18137: Detect integer overflow on precision in float.__format__()
+ and complex.__format__().
+
- Issue #18038: SyntaxError raised during compilation sources with illegal
encoding now always contains an encoding name.
diff --git a/Objects/stringlib/formatter.h b/Objects/stringlib/formatter.h
index 6b28224..fd22751 100644
--- a/Objects/stringlib/formatter.h
+++ b/Objects/stringlib/formatter.h
@@ -928,7 +928,7 @@
Py_ssize_t n_total;
int has_decimal;
double val;
- Py_ssize_t precision = format->precision;
+ Py_ssize_t precision;
Py_ssize_t default_precision = 6;
STRINGLIB_CHAR type = format->type;
int add_pct = 0;
@@ -947,6 +947,12 @@
from a hard-code pseudo-locale */
LocaleInfo locale;
+ if (format->precision > INT_MAX) {
+ PyErr_SetString(PyExc_ValueError, "precision too big");
+ goto done;
+ }
+ precision = (int)format->precision;
+
/* Alternate is not allowed on floats. */
if (format->alternate) {
PyErr_SetString(PyExc_ValueError,
@@ -1078,7 +1084,7 @@
Py_ssize_t n_im_total;
int re_has_decimal;
int im_has_decimal;
- Py_ssize_t precision = format->precision;
+ Py_ssize_t precision;
Py_ssize_t default_precision = 6;
STRINGLIB_CHAR type = format->type;
STRINGLIB_CHAR *p_re;
@@ -1107,6 +1113,12 @@
from a hard-code pseudo-locale */
LocaleInfo locale;
+ if (format->precision > INT_MAX) {
+ PyErr_SetString(PyExc_ValueError, "precision too big");
+ goto done;
+ }
+ precision = (int)format->precision;
+
/* Alternate is not allowed on complex. */
if (format->alternate) {
PyErr_SetString(PyExc_ValueError,