From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 31 Jul 2023 18:21:25 +0000 (-0700)
Subject: who: fix only-theoretical overflow
X-Git-Tag: v9.4~60
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9cbda6e1f8fdd4d7ffae26edcabceb239ed14ece;p=thirdparty%2Fcoreutils.git

who: fix only-theoretical overflow

Change stzncpy’s implementation to match its comment, in the case
where SRC + LEN would overflow.  This case never happens in coreutils.
* src/system.h (stzncpy): Work even if SRC + LEN would overflow.
---

diff --git a/src/system.h b/src/system.h
index db1a6773b9..2d9c47f48b 100644
--- a/src/system.h
+++ b/src/system.h
@@ -781,8 +781,8 @@ write_error (void)
 static inline char *
 stzncpy (char *restrict dest, char const *restrict src, size_t len)
 {
-  char const *src_end = src + len;
-  while (src < src_end && *src)
+  size_t i;
+  for (i = 0; i < len && *src; i++)
     *dest++ = *src++;
   *dest = 0;
   return dest;