From: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Mon, 24 Jan 2022 16:06:41 +0000 (+0530)
Subject: realpath: Avoid overwriting preexisting error (CVE-2021-3998)
X-Git-Tag: glibc-2.35~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=84d2d0fe20bdf94feed82b21b4d7d136db471f03;p=thirdparty%2Fglibc.git

realpath: Avoid overwriting preexisting error (CVE-2021-3998)

Set errno and failure for paths that are too long only if no other error
occurred earlier.

Related: BZ #28770

Reviewed-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
---

diff --git a/stdlib/canonicalize.c b/stdlib/canonicalize.c
index 732dc7ea46c..6caed9e70e1 100644
--- a/stdlib/canonicalize.c
+++ b/stdlib/canonicalize.c
@@ -404,7 +404,7 @@ error:
     {
       if (dest - rname <= get_path_max ())
 	rname = strcpy (resolved, rname);
-      else
+      else if (!failed)
 	{
 	  failed = true;
 	  __set_errno (ENAMETOOLONG);