From: Karel Zak <kzak@redhat.com>
Date: Mon, 12 Apr 2021 07:39:59 +0000 (+0200)
Subject: mesg: use only stat() to get the current terminal status
X-Git-Tag: v2.37-rc1~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c0246ce059503bbc078122a50d564ca36a66f348;p=thirdparty%2Futil-linux.git

mesg: use only stat() to get the current terminal status

open()+stat() does not work for example after su(1) (from root to
non-root). It seems better to use only stat() to get the current
terminal status.

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1906157
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/term-utils/mesg.c b/term-utils/mesg.c
index 56fb700946..cb0b493d3f 100644
--- a/term-utils/mesg.c
+++ b/term-utils/mesg.c
@@ -139,13 +139,9 @@ int main(int argc, char *argv[])
 			warnx(_("ttyname() failed, attempting to go around using: %s"), tty);
 	}
 
-	if ((fd = open(tty, O_RDONLY)) < 0)
-		err(MESG_EXIT_FAILURE, _("cannot open %s"), tty);
-	if (fstat(fd, &sb))
-		err(MESG_EXIT_FAILURE, _("stat of %s failed"), tty);
-
 	if (!*argv) {
-		close(fd);
+		if (stat(tty, &sb))
+			err(MESG_EXIT_FAILURE, _("stat of %s failed"), tty);
 		if (sb.st_mode & (S_IWGRP | S_IWOTH)) {
 			puts(_("is y"));
 			return IS_ALLOWED;
@@ -154,6 +150,11 @@ int main(int argc, char *argv[])
 		return IS_NOT_ALLOWED;
 	}
 
+	if ((fd = open(tty, O_RDONLY)) < 0)
+		err(MESG_EXIT_FAILURE, _("cannot open %s"), tty);
+	if (fstat(fd, &sb))
+		err(MESG_EXIT_FAILURE, _("stat of %s failed"), tty);
+
 	switch (rpmatch(argv[0])) {
 	case RPMATCH_YES:
 #ifdef USE_TTY_GROUP