[2.7] bpo-9194: Fix the bounds checking in winreg.c's fixupMultiSZ() (GH-12687) (GH-12916)

ZackerySpytz · miss-islington · commit 84efbaecaf50 · 2019-04-22T16:35:55.000-07:00
(cherry picked from commit 56ed864) https://bugs.python.org/issue9194
diff --git a/PC/_winreg.c b/PC/_winreg.c
@@ -727,7 +727,7 @@ fixupMultiSZ(char **str, char *data, int len)
     Q = data + len;
     for (P = data, i = 0; P < Q && *P != '\0'; P++, i++) {
         str[i] = P;
-        for(; *P != '\0'; P++)
+        for (; P < Q && *P != '\0'; P++)
             ;
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -727,7 +727,7 @@ fixupMultiSZ(char *str, char data, int len)`
`727`	`727`	`Q = data + len;`
`728`	`728`	`for (P = data, i = 0; P < Q && *P != '\0'; P++, i++) {`
`729`	`729`	`str[i] = P;`
`730`		`- for(; *P != '\0'; P++)`
	`730`	`+ for (; P < Q && *P != '\0'; P++)`
`731`	`731`	`;`
`732`	`732`	`}`
`733`	`733`	`}`