From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, TOTE Robot <oslab@tsinghua.edu.cn>,
        Tuo Li <islituo@gmail.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 135/355] media: s5p-mfc: fix possible null-pointer dereference in s5p_mfc_probe()
Date:   Mon, 15 Nov 2021 18:00:59 +0100
Message-Id: <20211115165318.169309793@linuxfoundation.org>
In-Reply-To: <20211115165313.549179499@linuxfoundation.org>
References: <20211115165313.549179499@linuxfoundation.org>
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From: Tuo Li <islituo@gmail.com>

[ Upstream commit 8515965e5e33f4feb56134348c95953f3eadfb26 ]

The variable pdev is assigned to dev->plat_dev, and dev->plat_dev is
checked in:
  if (!dev->plat_dev)

This indicates both dev->plat_dev and pdev can be NULL. If so, the
function dev_err() is called to print error information.
  dev_err(&pdev->dev, "No platform data specified\n");

However, &pdev->dev is an illegal address, and it is dereferenced in
dev_err().

To fix this possible null-pointer dereference, replace dev_err() with
mfc_err().

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/platform/s5p-mfc/s5p_mfc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index b776f83e395e0..f8a5ed6bb9d7a 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -1279,7 +1279,7 @@ static int s5p_mfc_probe(struct platform_device *pdev)
 	spin_lock_init(&dev->condlock);
 	dev->plat_dev = pdev;
 	if (!dev->plat_dev) {
-		dev_err(&pdev->dev, "No platform data specified\n");
+		mfc_err("No platform data specified\n");
 		return -ENODEV;
 	}
 
-- 
2.33.0