linux-kernel - [ 13/86] tty: set_termios/set_termiox should not return -EINTR

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: <20130226235914.276168626@linuxfoundation.org>
Date:	Tue, 26 Feb 2013 16:07:21 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Roman Rakus <rrakus@...hat.com>,
	Lingzhu Xiang <lxiang@...hat.com>,
	Oleg Nesterov <oleg@...hat.com>, Jiri Slaby <jslaby@...e.cz>
Subject: [ 13/86] tty: set_termios/set_termiox should not return -EINTR

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Oleg Nesterov <oleg@...hat.com>

commit 183d95cdd834381c594d3aa801c1f9f9c0c54fa9 upstream.

See https://bugzilla.redhat.com/show_bug.cgi?id=904907
read command causes bash to abort with double free or corruption (out).

A simple test-case from Roman:

	// Compile the reproducer and send sigchld ti that process.
	// EINTR occurs even if SA_RESTART flag is set.

	void handler(int sig)
	{
	}

	main()
	{
	  struct sigaction act;
	  act.sa_handler = handler;
	  act.sa_flags = SA_RESTART;
	  sigaction (SIGCHLD, &act, 0);
	  struct termio ttp;
	  ioctl(0, TCGETA, &ttp);
	  while(1)
	  {
	    if (ioctl(0, TCSETAW, ttp) < 0)
	      {
		if (errno == EINTR)
		{
		  fprintf(stderr, "BUG!"); return(1);
		}
	      }
	  }
	}

Change set_termios/set_termiox to return -ERESTARTSYS to fix this
particular problem.

I didn't dare to change other EINTR's in drivers/tty/, but they look
equally wrong.

Reported-by: Roman Rakus <rrakus@...hat.com>
Reported-by: Lingzhu Xiang <lxiang@...hat.com>
Signed-off-by: Oleg Nesterov <oleg@...hat.com>
Cc: Jiri Slaby <jslaby@...e.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/tty/tty_ioctl.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -617,7 +617,7 @@ static int set_termios(struct tty_struct
 	if (opt & TERMIOS_WAIT) {
 		tty_wait_until_sent(tty, 0);
 		if (signal_pending(current))
-			return -EINTR;
+			return -ERESTARTSYS;
 	}
 
 	tty_set_termios(tty, &tmp_termios);
@@ -684,7 +684,7 @@ static int set_termiox(struct tty_struct
 	if (opt & TERMIOS_WAIT) {
 		tty_wait_until_sent(tty, 0);
 		if (signal_pending(current))
-			return -EINTR;
+			return -ERESTARTSYS;
 	}
 
 	mutex_lock(&tty->termios_mutex);


--
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/