util-linux/setterm-resize-uninit-flags.patch

From: Chris Hofstaedtler <zeha@debian.org>
Date: Mon, 30 Oct 2023 22:59:33 +0100
Subject: setterm: avoid restoring flags from uninitialized memory
References: https://salsa.debian.org/debian/util-linux/-/raw/master/debian/patches/debian/setterm-resize-uninit-flags.patch?inline=false

Depending on the used compiler and flags, previously either F_SETFL was called
with 0 or with a random value. Never with the intended previous flags.

Signed-off-by: Chris Hofstaedtler <zeha@debian.org>
---
 term-utils/setterm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/term-utils/setterm.c b/term-utils/setterm.c
index 22afc76..a477d5d 100644
--- a/term-utils/setterm.c
+++ b/term-utils/setterm.c
@@ -846,7 +846,11 @@ static void tty_raw(struct termios *saved_attributes, int *saved_fl)
 {
 	struct termios tattr;
 
-	fcntl(STDIN_FILENO, F_GETFL, saved_fl);
+	*saved_fl = fcntl(STDIN_FILENO, F_GETFL);
+	if (*saved_fl == -1) {
+		err(EXIT_FAILURE, _("fcntl failed: %s"),
+		    strerror(errno));
+	}
 	tcgetattr(STDIN_FILENO, saved_attributes);
 	fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);
 	memcpy(&tattr, saved_attributes, sizeof(struct termios));
@@ -898,7 +902,7 @@ static int resizetty(void)
 	ssize_t rc;
 	struct winsize ws;
 	struct termios saved_attributes;
-	int saved_fl;
+	int saved_fl = 0;
 
 	if (!isatty(STDIN_FILENO))
 		errx(EXIT_FAILURE, _("stdin does not refer to a terminal"));