linux-kernel - [PATCH] n_tty: Ensure reader restarts worker for next reader

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1383850796-24300-1-git-send-email-peter@hurleysoftware.com>
Date:	Thu,  7 Nov 2013 13:59:46 -0500
From:	Peter Hurley <peter@...leysoftware.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	linux-kernel@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Mikael Pettersson <mikpelinux@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-serial@...r.kernel.org,
	Peter Hurley <peter@...leysoftware.com>, stable@...nel.org
Subject: [PATCH] n_tty: Ensure reader restarts worker for next reader

A departing reader must restart a flush_to_ldisc() worker _before_
the next reader enters the read loop; this is to avoid the new reader
concluding no more i/o is available and prematurely exiting, when the
old reader simply hasn't re-started the worker yet.

Cc: stable@...nel.org # 3.12
Signed-off-by: Peter Hurley <peter@...leysoftware.com>
---
 drivers/tty/n_tty.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 7a744b6..ce11cd5 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2250,6 +2250,9 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 		if (time)
 			timeout = time;
 	}
+	n_tty_set_room(tty);
+	up_read(&tty->termios_rwsem);
+
 	mutex_unlock(&ldata->atomic_read_lock);
 	remove_wait_queue(&tty->read_wait, &wait);
 
@@ -2260,8 +2263,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 	if (b - buf)
 		retval = b - buf;
 
-	n_tty_set_room(tty);
-	up_read(&tty->termios_rwsem);
 	return retval;
 }
 
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/