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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Nicolas Boichat <drinkcat@chromium.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.9 524/757] rpmsg: Avoid double-free in mtk_rpmsg_register_device
Date:   Tue, 27 Oct 2020 14:52:54 +0100
Message-Id: <20201027135515.063445707@linuxfoundation.org>
In-Reply-To: <20201027135450.497324313@linuxfoundation.org>
References: <20201027135450.497324313@linuxfoundation.org>
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From: Nicolas Boichat <drinkcat@chromium.org>

[ Upstream commit 231331b2dbd71487159a0400d9ffd967eb0d0e08 ]

If rpmsg_register_device fails, it will call
mtk_rpmsg_release_device which already frees mdev.

Fixes: 7017996951fd ("rpmsg: add rpmsg support for mt8183 SCP.")
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200903080547.v3.1.I56cf27cd59f4013bd074dc622c8b8248b034a4cc@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/rpmsg/mtk_rpmsg.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
index 83f2b8804ee98..96a17ec291401 100644
--- a/drivers/rpmsg/mtk_rpmsg.c
+++ b/drivers/rpmsg/mtk_rpmsg.c
@@ -200,7 +200,6 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
 	struct rpmsg_device *rpdev;
 	struct mtk_rpmsg_device *mdev;
 	struct platform_device *pdev = mtk_subdev->pdev;
-	int ret;
 
 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
 	if (!mdev)
@@ -219,13 +218,7 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
 	rpdev->dev.parent = &pdev->dev;
 	rpdev->dev.release = mtk_rpmsg_release_device;
 
-	ret = rpmsg_register_device(rpdev);
-	if (ret) {
-		kfree(mdev);
-		return ret;
-	}
-
-	return 0;
+	return rpmsg_register_device(rpdev);
 }
 
 static void mtk_register_device_work_function(struct work_struct *register_work)
-- 
2.25.1