Util-Linux package development
 help / color / mirror / Atom feed
From: Chris Hofstaedtler <zeha@debian.org>
To: util-linux@vger.kernel.org
Cc: Chris Hofstaedtler <zeha@debian.org>, Emanuele Rocca <ema@debian.org>
Subject: [PATCH] setterm: avoid restoring flags from uninitialized memory
Date: Tue, 31 Oct 2023 14:52:26 +0100	[thread overview]
Message-ID: <20231031135226.10243-1-zeha@debian.org> (raw)

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>
Tested-by: Emanuele Rocca <ema@debian.org>
---
 term-utils/setterm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/term-utils/setterm.c b/term-utils/setterm.c
index 1bf9a5bb4..92bf75a46 100644
--- a/term-utils/setterm.c
+++ b/term-utils/setterm.c
@@ -846,7 +846,10 @@ 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"));
+	}
 	tcgetattr(STDIN_FILENO, saved_attributes);
 	fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);
 	memcpy(&tattr, saved_attributes, sizeof(struct termios));
@@ -898,7 +901,7 @@ 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"));
-- 
2.42.0


             reply	other threads:[~2023-10-31 14:08 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-31 13:52 Chris Hofstaedtler [this message]
2023-11-01  2:55 ` [PATCH] setterm: avoid restoring flags from uninitialized memory Dragan Simic
2023-11-01 12:04 ` Karel Zak

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231031135226.10243-1-zeha@debian.org \
    --to=zeha@debian.org \
    --cc=ema@debian.org \
    --cc=util-linux@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox