From: Dave Jiang <dave.jiang@intel.com>
Date: Fri, 31 Jan 2020 17:58:39 +0000 (-0700)
Subject: dmaengine: fix null ptr check for __dma_async_device_channel_register()
X-Git-Tag: v5.6-rc1~52^2~1
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=5429b51f606cb82f315f68678b959112766f235e;p=linux.git

dmaengine: fix null ptr check for __dma_async_device_channel_register()

Add check to pointer after assignment before accessing members.

Fixes: d2fb0a043838: ("dmaengine: break out channel registration")

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158049351973.45445.3291586905226032744.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 7b1cefc3213a..3432dac695e5 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -962,6 +962,9 @@ static int __dma_async_device_channel_register(struct dma_device *device,
 
 	tchan = list_first_entry_or_null(&device->channels,
 					 struct dma_chan, device_node);
+	if (!tchan)
+		return -ENODEV;
+
 	if (tchan->dev) {
 		idr_ref = tchan->dev->idr_ref;
 	} else {