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-rw-r--r--Misc/NEWS2
-rw-r--r--Modules/binascii.c25
2 files changed, 18 insertions, 9 deletions
diff --git a/Misc/NEWS b/Misc/NEWS
index c3235de..b2f081c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -29,6 +29,8 @@ Core and Builtins
Library
-------
+- Issue #27760: Fix possible integer overflow in binascii.b2a_qp.
+
- Issue #27758: Fix possible integer overflow in the _csv module for large record
lengths.
diff --git a/Modules/binascii.c b/Modules/binascii.c
index a84badc7..829bde8 100644
--- a/Modules/binascii.c
+++ b/Modules/binascii.c
@@ -1365,6 +1365,7 @@ binascii_b2a_qp (PyObject *self, PyObject *args, PyObject *kwargs)
/* First, scan to see how many characters need to be encoded */
in = 0;
while (in < datalen) {
+ Py_ssize_t delta = 0;
if ((data[in] > 126) ||
(data[in] == '=') ||
(header && data[in] == '_') ||
@@ -1379,12 +1380,12 @@ binascii_b2a_qp (PyObject *self, PyObject *args, PyObject *kwargs)
if ((linelen + 3) >= MAXLINESIZE) {
linelen = 0;
if (crlf)
- odatalen += 3;
+ delta += 3;
else
- odatalen += 2;
+ delta += 2;
}
linelen += 3;
- odatalen += 3;
+ delta += 3;
in++;
}
else {
@@ -1396,11 +1397,11 @@ binascii_b2a_qp (PyObject *self, PyObject *args, PyObject *kwargs)
linelen = 0;
/* Protect against whitespace on end of line */
if (in && ((data[in-1] == ' ') || (data[in-1] == '\t')))
- odatalen += 2;
+ delta += 2;
if (crlf)
- odatalen += 2;
+ delta += 2;
else
- odatalen += 1;
+ delta += 1;
if (data[in] == '\r')
in += 2;
else
@@ -1412,15 +1413,21 @@ binascii_b2a_qp (PyObject *self, PyObject *args, PyObject *kwargs)
(linelen + 1) >= MAXLINESIZE) {
linelen = 0;
if (crlf)
- odatalen += 3;
+ delta += 3;
else
- odatalen += 2;
+ delta += 2;
}
linelen++;
- odatalen++;
+ delta++;
in++;
}
}
+ if (PY_SSIZE_T_MAX - delta < odatalen) {
+ PyBuffer_Release(&pdata);
+ PyErr_NoMemory();
+ return NULL;
+ }
+ odatalen += delta;
}
/* We allocate the output same size as input, this is overkill.