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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,
        Eugen Hristev <eugen.hristev@microchip.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Lee Jones <lee.jones@linaro.org>
Subject: [PATCH 4.9 113/125] media: atmel: atmel-isc: fix asd memory allocation
Date:   Wed,  4 Dec 2019 18:56:58 +0100
Message-Id: <20191204175325.992756023@linuxfoundation.org>
In-Reply-To: <20191204175308.377746305@linuxfoundation.org>
References: <20191204175308.377746305@linuxfoundation.org>
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From: Eugen Hristev <eugen.hristev@microchip.com>

commit 1e4e25c4959c10728fbfcc6a286f9503d32dfe02 upstream.

The subsystem will free the asd memory on notifier cleanup, if the asd is
added to the notifier.
However the memory is freed using kfree.
Thus, we cannot allocate the asd using devm_*
This can lead to crashes and problems.
To test this issue, just return an error at probe, but cleanup the
notifier beforehand.

Fixes: 106267444f ("[media] atmel-isc: add the Image Sensor Controller code")

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/media/platform/atmel/atmel-isc.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -1297,8 +1297,11 @@ static int isc_parse_dt(struct device *d
 			break;
 		}
 
-		subdev_entity->asd = devm_kzalloc(dev,
-				     sizeof(*subdev_entity->asd), GFP_KERNEL);
+		/* asd will be freed by the subsystem once it's added to the
+		 * notifier list
+		 */
+		subdev_entity->asd = kzalloc(sizeof(*subdev_entity->asd),
+					     GFP_KERNEL);
 		if (subdev_entity->asd == NULL) {
 			of_node_put(rem);
 			ret = -ENOMEM;
@@ -1432,6 +1435,7 @@ static int atmel_isc_probe(struct platfo
 						   &subdev_entity->notifier);
 		if (ret) {
 			dev_err(dev, "fail to register async notifier\n");
+			kfree(subdev_entity->asd);
 			goto cleanup_subdev;
 		}