fix possible overflow in encode_basestring_ascii (closes #23369)
diff --git a/Modules/_json.c b/Modules/_json.c
index 4bc585d..397037e 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -216,17 +216,24 @@
/* Compute the output size */
for (i = 0, output_size = 2; i < input_chars; i++) {
Py_UCS4 c = PyUnicode_READ(kind, input, i);
- if (S_CHAR(c))
- output_size++;
+ Py_ssize_t d;
+ if (S_CHAR(c)) {
+ d = 1;
+ }
else {
switch(c) {
case '\\': case '"': case '\b': case '\f':
case '\n': case '\r': case '\t':
- output_size += 2; break;
+ d = 2; break;
default:
- output_size += c >= 0x10000 ? 12 : 6;
+ d = c >= 0x10000 ? 12 : 6;
}
}
+ if (output_size > PY_SSIZE_T_MAX - d) {
+ PyErr_SetString(PyExc_OverflowError, "string is too long to escape");
+ return NULL;
+ }
+ output_size += d;
}
rval = PyUnicode_New(output_size, 127);