From: Chris Hofstaedtler 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 --- 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"));