diff options
Diffstat (limited to 'Modules/zlibmodule.c')
| -rw-r--r-- | Modules/zlibmodule.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c index 54ab9a1499..c78cf42d1d 100644 --- a/Modules/zlibmodule.c +++ b/Modules/zlibmodule.c @@ -931,8 +931,18 @@ PyZlib_adler32(PyObject *self, PyObject *args) /* Releasing the GIL for very small buffers is inefficient and may lower performance */ if (pbuf.len > 1024*5) { + unsigned char *buf = pbuf.buf; + Py_ssize_t len = pbuf.len; + Py_BEGIN_ALLOW_THREADS - adler32val = adler32(adler32val, pbuf.buf, pbuf.len); + /* Avoid truncation of length for very large buffers. adler32() takes + length as an unsigned int, which may be narrower than Py_ssize_t. */ + while (len > (size_t) UINT_MAX) { + adler32val = adler32(adler32val, buf, UINT_MAX); + buf += (size_t) UINT_MAX; + len -= (size_t) UINT_MAX; + } + adler32val = adler32(adler32val, buf, len); Py_END_ALLOW_THREADS } else { adler32val = adler32(adler32val, pbuf.buf, pbuf.len); @@ -959,8 +969,18 @@ PyZlib_crc32(PyObject *self, PyObject *args) /* Releasing the GIL for very small buffers is inefficient and may lower performance */ if (pbuf.len > 1024*5) { + unsigned char *buf = pbuf.buf; + Py_ssize_t len = pbuf.len; + Py_BEGIN_ALLOW_THREADS - signed_val = crc32(crc32val, pbuf.buf, pbuf.len); + /* Avoid truncation of length for very large buffers. crc32() takes + length as an unsigned int, which may be narrower than Py_ssize_t. */ + while (len > (size_t) UINT_MAX) { + crc32val = crc32(crc32val, buf, UINT_MAX); + buf += (size_t) UINT_MAX; + len -= (size_t) UINT_MAX; + } + signed_val = crc32(crc32val, buf, len); Py_END_ALLOW_THREADS } else { signed_val = crc32(crc32val, pbuf.buf, pbuf.len); |