bpo-41486: Fix initial buffer size can't > UINT32_MAX in zlib module (GH-25738)
* Fix initial buffer size can't > UINT32_MAX in zlib module
After commit f9bedb630e8a0b7d94e1c7e609b20dfaa2b22231, in 64-bit build,
if the initial buffer size > UINT32_MAX, ValueError will be raised.
These two functions are affected:
1. zlib.decompress(data, /, wbits=MAX_WBITS, bufsize=DEF_BUF_SIZE)
2. zlib.Decompress.flush([length])
This commit re-allows the size > UINT32_MAX.
* adds curly braces per PEP 7.
* Renames `Buffer_*` to `OutputBuffer_*` for clarity
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index fc63ca9..fe06094 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -19,8 +19,8 @@
/* On success, return value >= 0
On failure, return -1 */
static inline Py_ssize_t
-Buffer_InitAndGrow(_BlocksOutputBuffer *buffer, Py_ssize_t max_length,
- Bytef **next_out, uint32_t *avail_out)
+OutputBuffer_InitAndGrow(_BlocksOutputBuffer *buffer, Py_ssize_t max_length,
+ Bytef **next_out, uint32_t *avail_out)
{
Py_ssize_t allocated;
@@ -33,15 +33,17 @@ Buffer_InitAndGrow(_BlocksOutputBuffer *buffer, Py_ssize_t max_length,
/* On success, return value >= 0
On failure, return -1 */
static inline Py_ssize_t
-Buffer_InitWithSize(_BlocksOutputBuffer *buffer, Py_ssize_t init_size,
- Bytef **next_out, uint32_t *avail_out)
+OutputBuffer_InitWithSize(_BlocksOutputBuffer *buffer, Py_ssize_t init_size,
+ Bytef **next_out, uint32_t *avail_out)
{
Py_ssize_t allocated;
- if (init_size < 0 || (size_t)init_size > UINT32_MAX) {
- PyErr_SetString(PyExc_ValueError,
- "Initial buffer size should (0 <= size <= UINT32_MAX)");
- return -1;
+ if (init_size >= 0 && // ensure (size_t) cast is safe
+ (size_t)init_size > UINT32_MAX)
+ {
+ /* In 32-bit build, never reach this conditional branch.
+ The maximum block size accepted by zlib is UINT32_MAX. */
+ init_size = UINT32_MAX;
}
allocated = _BlocksOutputBuffer_InitWithSize(
@@ -53,8 +55,8 @@ Buffer_InitWithSize(_BlocksOutputBuffer *buffer, Py_ssize_t init_size,
/* On success, return value >= 0
On failure, return -1 */
static inline Py_ssize_t
-Buffer_Grow(_BlocksOutputBuffer *buffer,
- Bytef **next_out, uint32_t *avail_out)
+OutputBuffer_Grow(_BlocksOutputBuffer *buffer,
+ Bytef **next_out, uint32_t *avail_out)
{
Py_ssize_t allocated;
@@ -65,19 +67,19 @@ Buffer_Grow(_BlocksOutputBuffer *buffer,
}
static inline Py_ssize_t
-Buffer_GetDataSize(_BlocksOutputBuffer *buffer, uint32_t avail_out)
+OutputBuffer_GetDataSize(_BlocksOutputBuffer *buffer, uint32_t avail_out)
{
return _BlocksOutputBuffer_GetDataSize(buffer, (Py_ssize_t) avail_out);
}
static inline PyObject *
-Buffer_Finish(_BlocksOutputBuffer *buffer, uint32_t avail_out)
+OutputBuffer_Finish(_BlocksOutputBuffer *buffer, uint32_t avail_out)
{
return _BlocksOutputBuffer_Finish(buffer, (Py_ssize_t) avail_out);
}
static inline void
-Buffer_OnError(_BlocksOutputBuffer *buffer)
+OutputBuffer_OnError(_BlocksOutputBuffer *buffer)
{
_BlocksOutputBuffer_OnError(buffer);
}
@@ -248,7 +250,7 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
Byte *ibuf = data->buf;
Py_ssize_t ibuflen = data->len;
- if (Buffer_InitAndGrow(&buffer, -1, &zst.next_out, &zst.avail_out) < 0) {
+ if (OutputBuffer_InitAndGrow(&buffer, -1, &zst.next_out, &zst.avail_out) < 0) {
goto error;
}
@@ -280,7 +282,7 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
do {
if (zst.avail_out == 0) {
- if (Buffer_Grow(&buffer, &zst.next_out, &zst.avail_out) < 0) {
+ if (OutputBuffer_Grow(&buffer, &zst.next_out, &zst.avail_out) < 0) {
deflateEnd(&zst);
goto error;
}
@@ -304,7 +306,7 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
err = deflateEnd(&zst);
if (err == Z_OK) {
- RetVal = Buffer_Finish(&buffer, zst.avail_out);
+ RetVal = OutputBuffer_Finish(&buffer, zst.avail_out);
if (RetVal == NULL) {
goto error;
}
@@ -313,7 +315,7 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
else
zlib_error(state, zst, err, "while finishing compression");
error:
- Buffer_OnError(&buffer);
+ OutputBuffer_OnError(&buffer);
return NULL;
}
@@ -352,7 +354,7 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
bufsize = 1;
}
- if (Buffer_InitWithSize(&buffer, bufsize, &zst.next_out, &zst.avail_out) < 0) {
+ if (OutputBuffer_InitWithSize(&buffer, bufsize, &zst.next_out, &zst.avail_out) < 0) {
goto error;
}
@@ -385,7 +387,7 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
do {
if (zst.avail_out == 0) {
- if (Buffer_Grow(&buffer, &zst.next_out, &zst.avail_out) < 0) {
+ if (OutputBuffer_Grow(&buffer, &zst.next_out, &zst.avail_out) < 0) {
inflateEnd(&zst);
goto error;
}
@@ -428,13 +430,13 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
goto error;
}
- RetVal = Buffer_Finish(&buffer, zst.avail_out);
+ RetVal = OutputBuffer_Finish(&buffer, zst.avail_out);
if (RetVal != NULL) {
return RetVal;
}
error:
- Buffer_OnError(&buffer);
+ OutputBuffer_OnError(&buffer);
return NULL;
}
@@ -677,7 +679,7 @@ zlib_Compress_compress_impl(compobject *self, PyTypeObject *cls,
self->zst.next_in = data->buf;
Py_ssize_t ibuflen = data->len;
- if (Buffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {
+ if (OutputBuffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto error;
}
@@ -686,8 +688,9 @@ zlib_Compress_compress_impl(compobject *self, PyTypeObject *cls,
do {
if (self->zst.avail_out == 0) {
- if (Buffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0)
+ if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto error;
+ }
}
Py_BEGIN_ALLOW_THREADS
@@ -704,13 +707,13 @@ zlib_Compress_compress_impl(compobject *self, PyTypeObject *cls,
} while (ibuflen != 0);
- RetVal = Buffer_Finish(&buffer, self->zst.avail_out);
+ RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
if (RetVal != NULL) {
goto success;
}
error:
- Buffer_OnError(&buffer);
+ OutputBuffer_OnError(&buffer);
RetVal = NULL;
success:
LEAVE_ZLIB(self);
@@ -799,15 +802,16 @@ zlib_Decompress_decompress_impl(compobject *self, PyTypeObject *cls,
if (max_length < 0) {
PyErr_SetString(PyExc_ValueError, "max_length must be non-negative");
return NULL;
- } else if (max_length == 0)
+ } else if (max_length == 0) {
max_length = -1;
+ }
ENTER_ZLIB(self);
self->zst.next_in = data->buf;
ibuflen = data->len;
- if (Buffer_InitAndGrow(&buffer, max_length, &self->zst.next_out, &self->zst.avail_out) < 0) {
+ if (OutputBuffer_InitAndGrow(&buffer, max_length, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto abort;
}
@@ -816,10 +820,10 @@ zlib_Decompress_decompress_impl(compobject *self, PyTypeObject *cls,
do {
if (self->zst.avail_out == 0) {
- if (Buffer_GetDataSize(&buffer, self->zst.avail_out) == max_length) {
+ if (OutputBuffer_GetDataSize(&buffer, self->zst.avail_out) == max_length) {
goto save;
}
- if (Buffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
+ if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto abort;
}
}
@@ -865,13 +869,13 @@ zlib_Decompress_decompress_impl(compobject *self, PyTypeObject *cls,
goto abort;
}
- RetVal = Buffer_Finish(&buffer, self->zst.avail_out);
+ RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
if (RetVal != NULL) {
goto success;
}
abort:
- Buffer_OnError(&buffer);
+ OutputBuffer_OnError(&buffer);
RetVal = NULL;
success:
LEAVE_ZLIB(self);
@@ -911,13 +915,13 @@ zlib_Compress_flush_impl(compobject *self, PyTypeObject *cls, int mode)
self->zst.avail_in = 0;
- if (Buffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {
+ if (OutputBuffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto error;
}
do {
if (self->zst.avail_out == 0) {
- if (Buffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
+ if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto error;
}
}
@@ -954,13 +958,13 @@ zlib_Compress_flush_impl(compobject *self, PyTypeObject *cls, int mode)
goto error;
}
- RetVal = Buffer_Finish(&buffer, self->zst.avail_out);
+ RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
if (RetVal != NULL) {
goto success;
}
error:
- Buffer_OnError(&buffer);
+ OutputBuffer_OnError(&buffer);
RetVal = NULL;
success:
LEAVE_ZLIB(self);
@@ -1189,7 +1193,7 @@ zlib_Decompress_flush_impl(compobject *self, PyTypeObject *cls,
self->zst.next_in = data.buf;
ibuflen = data.len;
- if (Buffer_InitWithSize(&buffer, length, &self->zst.next_out, &self->zst.avail_out) < 0) {
+ if (OutputBuffer_InitWithSize(&buffer, length, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto abort;
}
@@ -1199,8 +1203,9 @@ zlib_Decompress_flush_impl(compobject *self, PyTypeObject *cls,
do {
if (self->zst.avail_out == 0) {
- if (Buffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0)
+ if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
goto abort;
+ }
}
Py_BEGIN_ALLOW_THREADS
@@ -1243,13 +1248,13 @@ zlib_Decompress_flush_impl(compobject *self, PyTypeObject *cls,
}
}
- RetVal = Buffer_Finish(&buffer, self->zst.avail_out);
+ RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
if (RetVal != NULL) {
goto success;
}
abort:
- Buffer_OnError(&buffer);
+ OutputBuffer_OnError(&buffer);
RetVal = NULL;
success:
PyBuffer_Release(&data);