[PATCH] media: s5p-mfc: Fix initialization of internal structures

[PATCH] media: s5p-mfc: Fix initialization of internal structures

[Marek Szyprowski]

Initialize members of the internal device and context structures as early
as possible to avoid access to uninitialized objects on initialization
failures. If loading firmware or creating of the hardware instance fails,
driver will access device or context queue in error handling path, which
might not be initialized yet, what causes kernel panic. Fix this by moving
initialization of all static members as early as possible.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/platform/s5p-mfc/s5p_mfc.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index bb0a5887c9a9..05fe82be6584 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -764,6 +764,7 @@ static int s5p_mfc_open(struct file *file)
 		ret = -ENOMEM;
 		goto err_alloc;
 	}
+	init_waitqueue_head(&ctx->queue);
 	v4l2_fh_init(&ctx->fh, vdev);
 	file->private_data = &ctx->fh;
 	v4l2_fh_add(&ctx->fh);
@@ -899,7 +900,6 @@ static int s5p_mfc_open(struct file *file)
 		mfc_err("Failed to initialize videobuf2 queue(output)\n");
 		goto err_queue_init;
 	}
-	init_waitqueue_head(&ctx->queue);
 	mutex_unlock(&dev->mfc_mutex);
 	mfc_debug_leave();
 	return ret;
@@ -1218,6 +1218,13 @@ static int s5p_mfc_probe(struct platform_device *pdev)
 	vb2_dma_contig_set_max_seg_size(dev->mem_dev_r, DMA_BIT_MASK(32));
 
 	mutex_init(&dev->mfc_mutex);
+	init_waitqueue_head(&dev->queue);
+	dev->hw_lock = 0;
+	INIT_WORK(&dev->watchdog_work, s5p_mfc_watchdog_worker);
+	atomic_set(&dev->watchdog_cnt, 0);
+	init_timer(&dev->watchdog_timer);
+	dev->watchdog_timer.data = (unsigned long)dev;
+	dev->watchdog_timer.function = s5p_mfc_watchdog;
 
 	ret = s5p_mfc_alloc_firmware(dev);
 	if (ret)
@@ -1226,7 +1233,6 @@ static int s5p_mfc_probe(struct platform_device *pdev)
 	ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
 	if (ret)
 		goto err_v4l2_dev_reg;
-	init_waitqueue_head(&dev->queue);
 
 	/* decoder */
 	vfd = video_device_alloc();
@@ -1263,13 +1269,6 @@ static int s5p_mfc_probe(struct platform_device *pdev)
 	video_set_drvdata(vfd, dev);
 	platform_set_drvdata(pdev, dev);
 
-	dev->hw_lock = 0;
-	INIT_WORK(&dev->watchdog_work, s5p_mfc_watchdog_worker);
-	atomic_set(&dev->watchdog_cnt, 0);
-	init_timer(&dev->watchdog_timer);
-	dev->watchdog_timer.data = (unsigned long)dev;
-	dev->watchdog_timer.function = s5p_mfc_watchdog;
-
 	/* Initialize HW ops and commands based on MFC version */
 	s5p_mfc_init_hw_ops(dev);
 	s5p_mfc_init_hw_cmds(dev);
-- 
1.9.1

Re: [PATCH] media: s5p-mfc: Fix initialization of internal structures

[Andrzej Hajda]

On 03.02.2017 15:05, Marek Szyprowski wrote:
> Initialize members of the internal device and context structures as early
> as possible to avoid access to uninitialized objects on initialization
> failures. If loading firmware or creating of the hardware instance fails,
> driver will access device or context queue in error handling path, which
> might not be initialized yet, what causes kernel panic. Fix this by moving
> initialization of all static members as early as possible.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

Acked-by: Andrzej Hajda <a.hajda@samsung.com>

Re: [PATCH] media: s5p-mfc: Fix initialization of internal structures

[Javier Martinez Canillas]

Hello Marek,

On 02/03/2017 11:05 AM, Marek Szyprowski wrote:
> Initialize members of the internal device and context structures as early
> as possible to avoid access to uninitialized objects on initialization
> failures. If loading firmware or creating of the hardware instance fails,
> driver will access device or context queue in error handling path, which
> might not be initialized yet, what causes kernel panic. Fix this by moving
> initialization of all static members as early as possible.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---

Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>

Also tested on an Exynos5422 Odroid XU4 and Exynos5800 Peach Pi:

Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America