patch "staging: speakup: fix tty-operation NULL derefs" added to tty-linus

This is a note to let you know that I've just added the patch titled

staging: speakup: fix tty-operation NULL derefs

to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From a1960e0f1639cb1f7a3d94521760fc73091f6640 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Wed, 30 Jan 2019 10:49:34 +0100
Subject: staging: speakup: fix tty-operation NULL derefs

The send_xchar() and tiocmset() tty operations are optional. Add the missing sanity checks to prevent user-space triggerable NULL-pointer dereferences.

---
 drivers/staging/speakup/spk_ttyio.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

index c92bbd05516e..005de0024dd4 100644
@@ -265,7 +265,8 @@ static void spk_ttyio_send_xchar(char ch)
 		return;
 	}
 
-	speakup_tty->ops->send_xchar(speakup_tty, ch);
+	if (speakup_tty->ops->send_xchar)
+		speakup_tty->ops->send_xchar(speakup_tty, ch);
 	mutex_unlock(&speakup_tty_mutex);
 }
 

@@ -277,7 +278,8 @@ static void spk_ttyio_tiocmset(unsigned int set, unsigned int clear)
 		return;
 	}
 
-	speakup_tty->ops->tiocmset(speakup_tty, set, clear);
+	if (speakup_tty->ops->tiocmset)
+		speakup_tty->ops->tiocmset(speakup_tty, set, clear);
 	mutex_unlock(&speakup_tty_mutex);
 }
 

2.20.1