oss-fuzz-451112368: fix found crash

Adam · Adam · commit d30f29ade144 · 2026-02-13T21:33:11.000Z
Signed-off-by: Adam &lt;adam@Adam-Workstation.lan&gt;
diff --git a/Parser/tokenizer/helpers.c b/Parser/tokenizer/helpers.c
@@ -494,8 +494,8 @@ valid_utf8(const unsigned char* s)
         return 0;
     }
     length = expected + 1;
-    for (; expected; expected--)
-        if (s[expected] < 0x80 || s[expected] >= 0xC0)
+    for (int i = 1; i <= expected; i++)
+        if (s[i] < 0x80 || s[i] >= 0xC0)
             return 0;
     return length;
 }

Original file line number	Diff line number	Diff line change
`@@ -494,8 +494,8 @@ valid_utf8(const unsigned char* s)`
`494`	`494`	`return 0;`
`495`	`495`	`}`
`496`	`496`	`length = expected + 1;`
`497`		`- for (; expected; expected--)`
`498`		`- if (s[expected] < 0x80 \|\| s[expected] >= 0xC0)`
	`497`	`+ for (int i = 1; i <= expected; i++)`
	`498`	`+ if (s[i] < 0x80 \|\| s[i] >= 0xC0)`
`499`	`499`	`return 0;`
`500`	`500`	`return length;`
`501`	`501`	`}`