tty: Make get_current_tty use a kref
We now return a kref covered tty reference. That ensures the tty structure
doesn't go away when you have a return from get_current_tty. This is not
enough to protect you from most of the resources being freed behind your
back - yet.
[Updated to include fixes for SELinux problems found by Andrew Morton and
an s390 leak found while debugging the former]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index d18e6d2..3ef5425 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -430,11 +430,12 @@
mutex_lock(&tty_mutex);
tty = get_current_tty();
if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
- mutex_unlock(&tty_mutex);
+ tty_kref_put(tty);
rc = -ENODEV;
goto out;
}
minor = tty->index + RAW3270_FIRSTMINOR;
+ tty_kref_put(tty);
mutex_unlock(&tty_mutex);
}
/* Check if some other program is already using fullscreen mode. */