[3.16.y-ckt stable] Patch "ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt25.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 7d9c7599c25da08ff6384ae7fc8cf06e6bdb05a4 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Mon, 1 Feb 2016 12:04:55 +0100
Subject: ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check

commit cc85f7a634cfaf9f0713c6aa06d08817424db37a upstream.

NULL user-space buffer can be passed even in a normal path, thus it's
not good to spew a kernel warning with stack trace at each time.
Just drop snd_BUG_ON() macro usage there.

BugLink: http://lkml.kernel.org/r/CACT4Y+YfVJ3L+q0i-4vyQVyyPD7V=OMX0PWPi29x9Bo3QaBLdw@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov at google.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 sound/core/rawmidi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 6fc71a4c8a51..1d9dbed43b84 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -1188,7 +1188,7 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
 	long count1, result;
 	struct snd_rawmidi_runtime *runtime = substream->runtime;

-	if (snd_BUG_ON(!kernelbuf && !userbuf))
+	if (!kernelbuf && !userbuf)
 		return -EINVAL;
 	if (snd_BUG_ON(!runtime->buffer))
 		return -EINVAL;