From: Alejandro Colomar <alx@kernel.org>
Date: Tue, 7 Nov 2023 17:03:08 +0000 (+0100)
Subject: lib/utmp.c: Replace strncpy(3) call by ZUSTR2STP()
X-Git-Tag: 4.15.0-rc1~125
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a1a097afa53238e727dd49236518a4c43d2f5c1;p=thirdparty%2Fshadow.git

lib/utmp.c: Replace strncpy(3) call by ZUSTR2STP()

We were copying from a (zero-padded) fixed-width character array to a
string, but strncpy(3) is meant to do the opposite thing.  ZUSTR2STP()
is designed to be used in this case (like strncat(3)).

Fixes: f40bdfa66a3a ("libmisc: implement `get_session_host()`")
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

diff --git a/lib/utmp.c b/lib/utmp.c
index fb5c093be..906a9fac3 100644
--- a/lib/utmp.c
+++ b/lib/utmp.c
@@ -169,8 +169,7 @@ int get_session_host (char **out)
 #ifdef HAVE_STRUCT_UTMP_UT_HOST
 	if ((ut != NULL) && (ut->ut_host[0] != '\0')) {
 		hostname = XMALLOC(sizeof(ut->ut_host) + 1, char);
-		strncpy (hostname, ut->ut_host, sizeof (ut->ut_host));
-		hostname[sizeof (ut->ut_host)] = '\0';
+		ZUSTR2STP(hostname, ut->ut_host);
 		*out = hostname;
 		free (ut);
 	} else {