patch "tty: Fix GPF in flush_to_ldisc(), part 2" added to tty-testing

patch "tty: Fix GPF in flush_to_ldisc(), part 2" added to tty-testing

[gregkh]

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

    tty: Fix GPF in flush_to_ldisc(), part 2

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-testing 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 be merged to the tty-next branch sometime soon,
after it passes testing, and the merge window is open.

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


>From f33798deecbd59a2955f40ac0ae2bc7dff54c069 Mon Sep 17 00:00:00 2001
From: Peter Hurley <peter@hurleysoftware.com>
Date: Sun, 10 Jan 2016 20:36:12 -0800
Subject: tty: Fix GPF in flush_to_ldisc(), part 2

commit 9ce119f318ba ("tty: Fix GPF in flush_to_ldisc()") fixed a
GPF caused by a line discipline which does not define a receive_buf()
method.

However, the vt driver (and speakup driver also) pushes selection
data directly to the line discipline receive_buf() method via
tty_ldisc_receive_buf(). Fix the same problem in tty_ldisc_receive_buf().

Cc: <stable@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/tty.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/tty.h b/include/linux/tty.h
index dea7d54d00d4..03e4015fa033 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -579,7 +579,7 @@ static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 		count = ld->ops->receive_buf2(ld->tty, p, f, count);
 	else {
 		count = min_t(int, count, ld->tty->receive_room);
-		if (count)
+		if (count && ld->ops->receive_buf)
 			ld->ops->receive_buf(ld->tty, p, f, count);
 	}
 	return count;
-- 
2.7.0