[PATCH 5.4 143/388] ASoC: SOF: ipc: check ipc return value before data copy

[Greg Kroah-Hartman]

From: Jaska Uimonen <jaska.uimonen@xxxxxxxxxxxxxxx>

[ Upstream commit 1919b42ca4ad75a2397081164661af3ce5a7b8f4 ]

In tx_wait_done the ipc payload is copied before the DSP transaction
error code is checked. This might lead to corrupted data in kernel side
even though the error would be handled later. It is also pointless to
copy the data in case of error. So change the order of error check and
copy.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Jaska Uimonen <jaska.uimonen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200228231850.9226-3-pierre-louis.bossart@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 sound/soc/sof/ipc.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/soc/sof/ipc.c b/sound/soc/sof/ipc.c
index e7b1a80e2a14c..f38f651da2246 100644
--- a/sound/soc/sof/ipc.c
+++ b/sound/soc/sof/ipc.c
@@ -215,15 +215,17 @@ static int tx_wait_done(struct snd_sof_ipc *ipc, struct snd_sof_ipc_msg *msg,
 		snd_sof_trace_notify_for_error(ipc->sdev);
 		ret = -ETIMEDOUT;
 	} else {
-		/* copy the data returned from DSP */
 		ret = msg->reply_error;
-		if (msg->reply_size)
-			memcpy(reply_data, msg->reply_data, msg->reply_size);
-		if (ret < 0)
+		if (ret < 0) {
 			dev_err(sdev->dev, "error: ipc error for 0x%x size %zu\n",
 				hdr->cmd, msg->reply_size);
-		else
+		} else {
 			ipc_log_header(sdev->dev, "ipc tx succeeded", hdr->cmd);
+			if (msg->reply_size)
+				/* copy the data returned from DSP */
+				memcpy(reply_data, msg->reply_data,
+				       msg->reply_size);
+		}
 	}
 
 	return ret;
-- 
2.25.1