This is a note to let you know that I've just added the patch titled tty: Prevent untrappable signals from malicious program to the 3.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tty-prevent-untrappable-signals-from-malicious-program.patch and it can be found in the queue-3.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 37480a05685ed5b8e1b9bf5e5c53b5810258b149 Mon Sep 17 00:00:00 2001 From: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> Date: Mon, 19 Jan 2015 13:05:03 -0500 Subject: tty: Prevent untrappable signals from malicious program From: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> commit 37480a05685ed5b8e1b9bf5e5c53b5810258b149 upstream. Commit 26df6d13406d1a5 ("tty: Add EXTPROC support for LINEMODE") allows a process which has opened a pty master to send _any_ signal to the process group of the pty slave. Although potentially exploitable by a malicious program running a setuid program on a pty slave, it's unknown if this exploit currently exists. Limit to signals actually used. Cc: Theodore Ts'o <tytso@xxxxxxx> Cc: Howard Chu <hyc@xxxxxxxxx> Cc: One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx> Cc: Jiri Slaby <jslaby@xxxxxxx> Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/pty.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -210,6 +210,9 @@ static int pty_signal(struct tty_struct { struct pid *pgrp; + if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP) + return -EINVAL; + if (tty->link) { pgrp = tty_get_pgrp(tty->link); if (pgrp) Patches currently in stable-queue which might be from peter@xxxxxxxxxxxxxxxxxx are queue-3.19/tty-prevent-untrappable-signals-from-malicious-program.patch queue-3.19/tty-remove-warning-in-tty_lock_slave.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html