bpo-32587: Fixes unsafe downcast in PC/winreg.c (GH-15766)

miss-islington · zooba · web-flow · commit 55a6f73b4962 · 2019-09-09T07:25:20.000-07:00
(cherry picked from commit ef66f31) Co-authored-by: Steve Dower <steve.dower@python.org>
diff --git a/PC/winreg.c b/PC/winreg.c
@@ -772,7 +772,7 @@ Reg2Py(BYTE *retDataBuf, DWORD retDataSize, DWORD typ)
                         return NULL;
                     }
                     PyList_SET_ITEM(obData, index, uni);
-                    len -= slen + 1;
+                    len -= Py_SAFE_DOWNCAST(slen + 1, size_t, int);
                 }
                 PyMem_Free(str);
 

Original file line number	Diff line number	Diff line change
`@@ -772,7 +772,7 @@ Reg2Py(BYTE *retDataBuf, DWORD retDataSize, DWORD typ)`
`772`	`772`	`return NULL;`
`773`	`773`	`}`
`774`	`774`	`PyList_SET_ITEM(obData, index, uni);`
`775`		`- len -= slen + 1;`
	`775`	`+ len -= Py_SAFE_DOWNCAST(slen + 1, size_t, int);`
`776`	`776`	`}`
`777`	`777`	`PyMem_Free(str);`
`778`	`778`