From 4ee824be757337d8444fdc320aa1ca3e4397c906 Mon Sep 17 00:00:00 2001
From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Tue, 21 Jun 2022 15:57:48 +0100
Subject: [PATCH] Fix invalid pointer dereference in wcpcpy_chk

The src pointer is const and points to a different object, so accessing
dest via src is invalid.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
---
 debug/wcpcpy_chk.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/debug/wcpcpy_chk.c b/debug/wcpcpy_chk.c
index 0e1d381a..16410e17 100644
--- a/debug/wcpcpy_chk.c
+++ b/debug/wcpcpy_chk.c
@@ -29,13 +29,12 @@ __wcpcpy_chk (wchar_t *dest, const wchar_t *src, size_t destlen)
 {
   wchar_t *wcp = (wchar_t *) dest - 1;
   wint_t c;
-  const ptrdiff_t off = src - dest + 1;
 
   do
     {
       if (__glibc_unlikely (destlen-- == 0))
 	__chk_fail ();
-      c = wcp[off];
+      c = *src++;
       *++wcp = c;
     }
   while (c != L'\0');
-- 
2.27.0

