Commit d9c1e9a8 authored Mar 18, 2007 by Eric W. Biederman Committed by Linus Torvalds Mar 18, 2007

[PATCH] tty: Fix two reported pid leaks

These leaks were reported by: Catalin Marinas <catalin.marians@gmail.com>
and I have been able to very by inspection they are possible.

When converting tty_io.c to store pids as struct pid pointers instead
of pid_t values it appears I overlooked two places where we stop using
the pid value. The very obvious one is in do_tty_hangup, and the one
the less obvious one in __proc_set_tty.

When looking into the code __proc_set_tty only has pids that need to
be put because of failures of other parts of the code to properly
perform hangup processing. Fixing the leak here in __proc_set_tty
is easy and obviously correct so I am doing that first.

Fixing the places that should be performing hangup processing is much
less obviously correct. So those I'm aiming those patches at -mm.
for now, so the can age a while before they are merged.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent aeb3f6d1

drivers/char/tty_io.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1376,6 +1376,8 @@ static void do_tty_hangup(struct work_struct *work)
		read_unlock(&tasklist_lock);

		tty->flags = 0;
		put_pid(tty->session);
		put_pid(tty->pgrp);
		tty->session = NULL;
		tty->pgrp = NULL;
		tty->ctrl_status = 0;
		@@ -3841,6 +3843,9 @@ static struct pid __proc_set_tty(struct task_struct tsk, struct tty_struct *tt
		{
		struct pid *old_pgrp;
		if (tty) {
		/* We should not have a session or pgrp to here but.... */
		put_pid(tty->session);
		put_pid(tty->pgrp);
		tty->session = get_pid(task_session(tsk));
		tty->pgrp = get_pid(task_pgrp(tsk));
		}