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| author | Benjamin Peterson <benjamin@python.org> | 2016-08-14 01:33:33 (GMT) |
|---|---|---|
| committer | Benjamin Peterson <benjamin@python.org> | 2016-08-14 01:33:33 (GMT) |
| commit | 4f976513efd8d411126e09d036842d0691c49c82 (patch) | |
| tree | 99d85f9acb90e9f3cd36f735b41ed0e03a88eaa1 /Modules/binascii.c | |
| parent | 6e01d90cc8bfac920bd4f7143b3968a8a21079d9 (diff) | |
| download | cpython-4f976513efd8d411126e09d036842d0691c49c82.zip cpython-4f976513efd8d411126e09d036842d0691c49c82.tar.gz cpython-4f976513efd8d411126e09d036842d0691c49c82.tar.bz2 | |
fix possible integer overflow in binascii.b2a_qp (closes #27760)
Reported by Thomas E. Hybel
Diffstat (limited to 'Modules/binascii.c')
| -rw-r--r-- | Modules/binascii.c | 25 |
1 files changed, 16 insertions, 9 deletions
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. |