From 5e99456c20f712dcc13d9f6ca4278937d5367355 Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Date: Mon, 19 Nov 2018 10:33:44 -0500
Subject: [PATCH] media: videobuf2-v4l2: drop WARN_ON in vb2_warn_zero_bytesused()
Git-commit: 5e99456c20f712dcc13d9f6ca4278937d5367355
Patch-mainline: v5.0-rc1
References: CVE-2019-9455 bsc#1170345

Userspace shouldn't set bytesused to 0 for output buffers.
vb2_warn_zero_bytesused() warns about this (only once!), but it also
calls WARN_ON(1), which is confusing since it is not immediately clear
that it warns about a 0 value for bytesused.

Just drop the WARN_ON as it serves no purpose.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/v4l2-core/videobuf2-v4l2.c |    1 -
 1 file changed, 1 deletion(-)

--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -145,7 +145,6 @@ static void vb2_warn_zero_bytesused(stru
 		return;
 
 	check_once = true;
-	WARN_ON(1);
 
 	pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
 	if (vb->vb2_queue->allow_zero_bytesused)