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* [PATCH] media: rga: fix NULL pointer dereferences
@ 2019-03-09  6:35 ` Kangjie Lu
  0 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-09  6:35 UTC (permalink / raw)
  To: kjlu
  Cc: pakki001, Jacob chen, Mauro Carvalho Chehab, Heiko Stuebner,
	linux-media, linux-arm-kernel, linux-rockchip, linux-kernel

In case __get_free_pages fails, return -ENOMEM to avoid NULL
pointer dereferences.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..d42b214977a9 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -892,8 +892,13 @@ static int rga_probe(struct platform_device *pdev)
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages)
+		return -ENOMEM;
+
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->dst_mmu_pages)
+		return -ENOMEM;
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH] media: rga: fix NULL pointer dereferences
@ 2019-03-09  6:35 ` Kangjie Lu
  0 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-09  6:35 UTC (permalink / raw)
  To: kjlu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

In case __get_free_pages fails, return -ENOMEM to avoid NULL
pointer dereferences.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..d42b214977a9 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -892,8 +892,13 @@ static int rga_probe(struct platform_device *pdev)
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages)
+		return -ENOMEM;
+
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->dst_mmu_pages)
+		return -ENOMEM;
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH] media: rga: fix NULL pointer dereferences
  2019-03-09  6:35 ` Kangjie Lu
@ 2019-03-11 13:15   ` Steven Price
  -1 siblings, 0 replies; 16+ messages in thread
From: Steven Price @ 2019-03-11 13:15 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

On 09/03/2019 06:35, Kangjie Lu wrote:
> In case __get_free_pages fails, return -ENOMEM to avoid NULL
> pointer dereferences.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>  drivers/media/platform/rockchip/rga/rga.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..d42b214977a9 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -892,8 +892,13 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages)
> +		return -ENOMEM;
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages)
> +		return -ENOMEM;

I believe you need to perform clean up when probe fails, not just return
early, e.g. with a 'goto' to the existing clean up code at the end of
the function.

Also from what I can tell there is already a potential memory leak if
video_register_device() fails. You probably want something more like the
(completely untested) change below.

Steve

----8<----
diff --git a/drivers/media/platform/rockchip/rga/rga.c
b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..8df1945594ab 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -895,6 +895,11 @@ static int rga_probe(struct platform_device *pdev)
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);

+	if (!rga->src_mmu_pages || !rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_mem;
+	}
+
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;

@@ -911,6 +916,9 @@ static int rga_probe(struct platform_device *pdev)

 rel_vdev:
 	video_device_release(vfd);
+free_mem:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
 unreg_video_dev:
 	video_unregister_device(rga->vfd);
 unreg_v4l2_dev:

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH] media: rga: fix NULL pointer dereferences
@ 2019-03-11 13:15   ` Steven Price
  0 siblings, 0 replies; 16+ messages in thread
From: Steven Price @ 2019-03-11 13:15 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

On 09/03/2019 06:35, Kangjie Lu wrote:
> In case __get_free_pages fails, return -ENOMEM to avoid NULL
> pointer dereferences.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>  drivers/media/platform/rockchip/rga/rga.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..d42b214977a9 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -892,8 +892,13 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages)
> +		return -ENOMEM;
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages)
> +		return -ENOMEM;

I believe you need to perform clean up when probe fails, not just return
early, e.g. with a 'goto' to the existing clean up code at the end of
the function.

Also from what I can tell there is already a potential memory leak if
video_register_device() fails. You probably want something more like the
(completely untested) change below.

Steve

----8<----
diff --git a/drivers/media/platform/rockchip/rga/rga.c
b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..8df1945594ab 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -895,6 +895,11 @@ static int rga_probe(struct platform_device *pdev)
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);

+	if (!rga->src_mmu_pages || !rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_mem;
+	}
+
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;

@@ -911,6 +916,9 @@ static int rga_probe(struct platform_device *pdev)

 rel_vdev:
 	video_device_release(vfd);
+free_mem:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
 unreg_video_dev:
 	video_unregister_device(rga->vfd);
 unreg_v4l2_dev:

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v2] media: rga: fix NULL pointer dereferences and a memory leak
  2019-03-11 13:15   ` Steven Price
@ 2019-03-12  6:58     ` Kangjie Lu
  -1 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-12  6:58 UTC (permalink / raw)
  To: kjlu
  Cc: pakki001, Jacob chen, Mauro Carvalho Chehab, Heiko Stuebner,
	linux-media, linux-arm-kernel, linux-rockchip, linux-kernel

In case __get_free_pages fails, the fix releases resources and
return -ENOMEM to avoid NULL pointer dereferences.

Also, the fix frees pages when video_register_device fails to
avoid a memory leak.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..307b7ab0ab64 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -892,8 +892,17 @@ static int rga_probe(struct platform_device *pdev)
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages) {
+		ret = -ENOMEM;
+		goto rel_vdev;
+	}
+
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dst_pages;
+	}
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
@@ -901,7 +910,7 @@ static int rga_probe(struct platform_device *pdev)
 	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
 	if (ret) {
 		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
-		goto rel_vdev;
+		goto free_pages;
 	}
 
 	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -909,6 +918,10 @@ static int rga_probe(struct platform_device *pdev)
 
 	return 0;
 
+free_pages:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dst_pages:
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
 rel_vdev:
 	video_device_release(vfd);
 unreg_video_dev:
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v2] media: rga: fix NULL pointer dereferences and a memory leak
@ 2019-03-12  6:58     ` Kangjie Lu
  0 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-12  6:58 UTC (permalink / raw)
  To: kjlu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

In case __get_free_pages fails, the fix releases resources and
return -ENOMEM to avoid NULL pointer dereferences.

Also, the fix frees pages when video_register_device fails to
avoid a memory leak.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..307b7ab0ab64 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -892,8 +892,17 @@ static int rga_probe(struct platform_device *pdev)
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages) {
+		ret = -ENOMEM;
+		goto rel_vdev;
+	}
+
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dst_pages;
+	}
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
@@ -901,7 +910,7 @@ static int rga_probe(struct platform_device *pdev)
 	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
 	if (ret) {
 		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
-		goto rel_vdev;
+		goto free_pages;
 	}
 
 	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -909,6 +918,10 @@ static int rga_probe(struct platform_device *pdev)
 
 	return 0;
 
+free_pages:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dst_pages:
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
 rel_vdev:
 	video_device_release(vfd);
 unreg_video_dev:
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH v2] media: rga: fix NULL pointer dereferences and a memory leak
  2019-03-12  6:58     ` Kangjie Lu
@ 2019-03-13 13:35       ` Steven Price
  -1 siblings, 0 replies; 16+ messages in thread
From: Steven Price @ 2019-03-13 13:35 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

On 12/03/2019 06:58, Kangjie Lu wrote:
> In case __get_free_pages fails, the fix releases resources and
> return -ENOMEM to avoid NULL pointer dereferences.
> 
> Also, the fix frees pages when video_register_device fails to
> avoid a memory leak.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>  drivers/media/platform/rockchip/rga/rga.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..307b7ab0ab64 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -892,8 +892,17 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto rel_vdev;
> +	}
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dst_pages;
> +	}
>  
>  	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>  	def_frame.size = def_frame.stride * def_frame.height;
> @@ -901,7 +910,7 @@ static int rga_probe(struct platform_device *pdev)
>  	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>  	if (ret) {
>  		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
> -		goto rel_vdev;
> +		goto free_pages;
>  	}
>  
>  	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
> @@ -909,6 +918,10 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> +free_pages:
> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
> +free_dst_pages:
> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);
>  rel_vdev:
>  	video_device_release(vfd);
>  unreg_video_dev:

That looks good. However looking into the error path more closely it
appears that this was already rather broken. Here's the original:

> rel_vdev:
> 	video_device_release(vfd);
> unreg_video_dev:
> 	video_unregister_device(rga->vfd);
> unreg_v4l2_dev:
> 	v4l2_device_unregister(&rga->v4l2_dev);
> err_put_clk:
> 	pm_runtime_disable(rga->dev);

video_device_release() is simply a call to kfree(), but
video_unregister_device will then be called with the same pointer
(rga->vfd is set to vfd further up). Which will then cause a
use-after-free on the pointer.

It might be a good idea to test this error path, for example make the
video_register_device() call always fail and run with memory debuggers
enabled (e.g. CONFIG_KASAN or CONFIG_DEBUG_KMEM_LEAK).

Steve

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v2] media: rga: fix NULL pointer dereferences and a memory leak
@ 2019-03-13 13:35       ` Steven Price
  0 siblings, 0 replies; 16+ messages in thread
From: Steven Price @ 2019-03-13 13:35 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

On 12/03/2019 06:58, Kangjie Lu wrote:
> In case __get_free_pages fails, the fix releases resources and
> return -ENOMEM to avoid NULL pointer dereferences.
> 
> Also, the fix frees pages when video_register_device fails to
> avoid a memory leak.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>  drivers/media/platform/rockchip/rga/rga.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..307b7ab0ab64 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -892,8 +892,17 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto rel_vdev;
> +	}
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dst_pages;
> +	}
>  
>  	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>  	def_frame.size = def_frame.stride * def_frame.height;
> @@ -901,7 +910,7 @@ static int rga_probe(struct platform_device *pdev)
>  	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>  	if (ret) {
>  		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
> -		goto rel_vdev;
> +		goto free_pages;
>  	}
>  
>  	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
> @@ -909,6 +918,10 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> +free_pages:
> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
> +free_dst_pages:
> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);
>  rel_vdev:
>  	video_device_release(vfd);
>  unreg_video_dev:

That looks good. However looking into the error path more closely it
appears that this was already rather broken. Here's the original:

> rel_vdev:
> 	video_device_release(vfd);
> unreg_video_dev:
> 	video_unregister_device(rga->vfd);
> unreg_v4l2_dev:
> 	v4l2_device_unregister(&rga->v4l2_dev);
> err_put_clk:
> 	pm_runtime_disable(rga->dev);

video_device_release() is simply a call to kfree(), but
video_unregister_device will then be called with the same pointer
(rga->vfd is set to vfd further up). Which will then cause a
use-after-free on the pointer.

It might be a good idea to test this error path, for example make the
video_register_device() call always fail and run with memory debuggers
enabled (e.g. CONFIG_KASAN or CONFIG_DEBUG_KMEM_LEAK).

Steve

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
  2019-03-13 13:35       ` Steven Price
@ 2019-03-14  5:03         ` Kangjie Lu
  -1 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-14  5:03 UTC (permalink / raw)
  To: kjlu
  Cc: pakki001, Jacob chen, Mauro Carvalho Chehab, Heiko Stuebner,
	linux-media, linux-arm-kernel, linux-rockchip, linux-kernel

1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
Further uses of their return values lead to NULL pointer
dereferences

2. In the error-handling path, video_unregister_device uses
"rga->vfd" which has been freed by video_device_release

3. The error handling for v4l2_m2m_init and video_register_device
has memory-leak issues

The patch fixes the above issues.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..468365ceb99d 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
 	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
 					   &rga->cmdbuf_phy, GFP_KERNEL,
 					   DMA_ATTR_WRITE_COMBINE);
+	if (!rga->cmdbuf_virt) {
+		ret = -ENOMEM;
+		goto unreg_video_dev;
+	}
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dma_attrs;
+	}
+
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dst_pages;
+	}
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
@@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
 	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
 	if (ret) {
 		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
-		goto rel_vdev;
+		goto free_pages;
 	}
 
 	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
 
 	return 0;
 
-rel_vdev:
-	video_device_release(vfd);
+free_pages:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dst_pages:
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
+free_dma_attrs:
+	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
+		       rga->cmdbuf_phy,
+		       DMA_ATTR_WRITE_COMBINE);
 unreg_video_dev:
 	video_unregister_device(rga->vfd);
+	video_device_release(vfd);
 unreg_v4l2_dev:
 	v4l2_device_unregister(&rga->v4l2_dev);
 err_put_clk:
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
@ 2019-03-14  5:03         ` Kangjie Lu
  0 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-14  5:03 UTC (permalink / raw)
  To: kjlu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
Further uses of their return values lead to NULL pointer
dereferences

2. In the error-handling path, video_unregister_device uses
"rga->vfd" which has been freed by video_device_release

3. The error handling for v4l2_m2m_init and video_register_device
has memory-leak issues

The patch fixes the above issues.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..468365ceb99d 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
 	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
 					   &rga->cmdbuf_phy, GFP_KERNEL,
 					   DMA_ATTR_WRITE_COMBINE);
+	if (!rga->cmdbuf_virt) {
+		ret = -ENOMEM;
+		goto unreg_video_dev;
+	}
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dma_attrs;
+	}
+
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dst_pages;
+	}
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
@@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
 	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
 	if (ret) {
 		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
-		goto rel_vdev;
+		goto free_pages;
 	}
 
 	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
 
 	return 0;
 
-rel_vdev:
-	video_device_release(vfd);
+free_pages:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dst_pages:
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
+free_dma_attrs:
+	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
+		       rga->cmdbuf_phy,
+		       DMA_ATTR_WRITE_COMBINE);
 unreg_video_dev:
 	video_unregister_device(rga->vfd);
+	video_device_release(vfd);
 unreg_v4l2_dev:
 	v4l2_device_unregister(&rga->v4l2_dev);
 err_put_clk:
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
  2019-03-14  5:03         ` Kangjie Lu
@ 2019-03-14 10:30           ` Steven Price
  -1 siblings, 0 replies; 16+ messages in thread
From: Steven Price @ 2019-03-14 10:30 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

On 14/03/2019 05:03, Kangjie Lu wrote:
> 1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
> Further uses of their return values lead to NULL pointer
> dereferences
> 
> 2. In the error-handling path, video_unregister_device uses
> "rga->vfd" which has been freed by video_device_release
> 
> 3. The error handling for v4l2_m2m_init and video_register_device
> has memory-leak issues
> 
> The patch fixes the above issues.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>

Reviewed-by: Steven Price <steven.price@arm.com>

Yes, that looks like it solves the issues with the clean up - thanks for
reworking it!

> ---
>  drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..468365ceb99d 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
>  	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
>  					   &rga->cmdbuf_phy, GFP_KERNEL,
>  					   DMA_ATTR_WRITE_COMBINE);
> +	if (!rga->cmdbuf_virt) {
> +		ret = -ENOMEM;
> +		goto unreg_video_dev;
> +	}
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dma_attrs;
> +	}
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dst_pages;
> +	}
>  
>  	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>  	def_frame.size = def_frame.stride * def_frame.height;
> @@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
>  	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>  	if (ret) {
>  		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
> -		goto rel_vdev;
> +		goto free_pages;
>  	}
>  
>  	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
> @@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> -rel_vdev:
> -	video_device_release(vfd);
> +free_pages:
> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
> +free_dst_pages:
> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);

Minor comment: free_pages accepts a NULL pointer (or more precisely 0,
since it takes an unsigned long), it just returns having done nothing.
So there isn't actually any harm in calling free_pages unconditionally
in the error path (since rga is initialised to all zeros). You can save
a couple of labels in the error path using that trick.

Thanks,

Steve

> +free_dma_attrs:
> +	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
> +		       rga->cmdbuf_phy,
> +		       DMA_ATTR_WRITE_COMBINE);
>  unreg_video_dev:
>  	video_unregister_device(rga->vfd);
> +	video_device_release(vfd);
>  unreg_v4l2_dev:
>  	v4l2_device_unregister(&rga->v4l2_dev);
>  err_put_clk:
> 


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
@ 2019-03-14 10:30           ` Steven Price
  0 siblings, 0 replies; 16+ messages in thread
From: Steven Price @ 2019-03-14 10:30 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

On 14/03/2019 05:03, Kangjie Lu wrote:
> 1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
> Further uses of their return values lead to NULL pointer
> dereferences
> 
> 2. In the error-handling path, video_unregister_device uses
> "rga->vfd" which has been freed by video_device_release
> 
> 3. The error handling for v4l2_m2m_init and video_register_device
> has memory-leak issues
> 
> The patch fixes the above issues.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>

Reviewed-by: Steven Price <steven.price@arm.com>

Yes, that looks like it solves the issues with the clean up - thanks for
reworking it!

> ---
>  drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..468365ceb99d 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
>  	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
>  					   &rga->cmdbuf_phy, GFP_KERNEL,
>  					   DMA_ATTR_WRITE_COMBINE);
> +	if (!rga->cmdbuf_virt) {
> +		ret = -ENOMEM;
> +		goto unreg_video_dev;
> +	}
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dma_attrs;
> +	}
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dst_pages;
> +	}
>  
>  	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>  	def_frame.size = def_frame.stride * def_frame.height;
> @@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
>  	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>  	if (ret) {
>  		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
> -		goto rel_vdev;
> +		goto free_pages;
>  	}
>  
>  	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
> @@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> -rel_vdev:
> -	video_device_release(vfd);
> +free_pages:
> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
> +free_dst_pages:
> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);

Minor comment: free_pages accepts a NULL pointer (or more precisely 0,
since it takes an unsigned long), it just returns having done nothing.
So there isn't actually any harm in calling free_pages unconditionally
in the error path (since rga is initialised to all zeros). You can save
a couple of labels in the error path using that trick.

Thanks,

Steve

> +free_dma_attrs:
> +	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
> +		       rga->cmdbuf_phy,
> +		       DMA_ATTR_WRITE_COMBINE);
>  unreg_video_dev:
>  	video_unregister_device(rga->vfd);
> +	video_device_release(vfd);
>  unreg_v4l2_dev:
>  	v4l2_device_unregister(&rga->v4l2_dev);
>  err_put_clk:
> 


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
  2019-03-14  5:03         ` Kangjie Lu
@ 2019-03-28 14:47           ` Hans Verkuil
  -1 siblings, 0 replies; 16+ messages in thread
From: Hans Verkuil @ 2019-03-28 14:47 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: pakki001, Jacob chen, Mauro Carvalho Chehab, Heiko Stuebner,
	linux-media, linux-arm-kernel, linux-rockchip, linux-kernel

Hi Kangjie,

Unfortunately there are more issues with the cleanup sequence in
this probe function:

On 3/14/19 6:03 AM, Kangjie Lu wrote:
> 1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
> Further uses of their return values lead to NULL pointer
> dereferences
> 
> 2. In the error-handling path, video_unregister_device uses
> "rga->vfd" which has been freed by video_device_release
> 
> 3. The error handling for v4l2_m2m_init and video_register_device
> has memory-leak issues
> 
> The patch fixes the above issues.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>  drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..468365ceb99d 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
>  	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
>  					   &rga->cmdbuf_phy, GFP_KERNEL,
>  					   DMA_ATTR_WRITE_COMBINE);
> +	if (!rga->cmdbuf_virt) {
> +		ret = -ENOMEM;
> +		goto unreg_video_dev;

Actually, the unreg_video_dev label makes no sense: if the video device
is successfully registered, then probe() returns 0. So you never need to
unregister the video device again. You *do* need to release it with
video_device_release().

So this should be a goto rel_vdev.

And the cleanup sequence at the end also fails to call v4l2_m2m_release().

Can you make v4?

Thanks!

	Hans

> +	}
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dma_attrs;
> +	}
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dst_pages;
> +	}
>  
>  	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>  	def_frame.size = def_frame.stride * def_frame.height;
> @@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
>  	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>  	if (ret) {
>  		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
> -		goto rel_vdev;
> +		goto free_pages;
>  	}
>  
>  	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
> @@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> -rel_vdev:
> -	video_device_release(vfd);
> +free_pages:
> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
> +free_dst_pages:
> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);
> +free_dma_attrs:
> +	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
> +		       rga->cmdbuf_phy,
> +		       DMA_ATTR_WRITE_COMBINE);
>  unreg_video_dev:
>  	video_unregister_device(rga->vfd);
> +	video_device_release(vfd);
>  unreg_v4l2_dev:
>  	v4l2_device_unregister(&rga->v4l2_dev);
>  err_put_clk:
> 


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
@ 2019-03-28 14:47           ` Hans Verkuil
  0 siblings, 0 replies; 16+ messages in thread
From: Hans Verkuil @ 2019-03-28 14:47 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media

Hi Kangjie,

Unfortunately there are more issues with the cleanup sequence in
this probe function:

On 3/14/19 6:03 AM, Kangjie Lu wrote:
> 1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
> Further uses of their return values lead to NULL pointer
> dereferences
> 
> 2. In the error-handling path, video_unregister_device uses
> "rga->vfd" which has been freed by video_device_release
> 
> 3. The error handling for v4l2_m2m_init and video_register_device
> has memory-leak issues
> 
> The patch fixes the above issues.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
>  drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..468365ceb99d 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
>  	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
>  					   &rga->cmdbuf_phy, GFP_KERNEL,
>  					   DMA_ATTR_WRITE_COMBINE);
> +	if (!rga->cmdbuf_virt) {
> +		ret = -ENOMEM;
> +		goto unreg_video_dev;

Actually, the unreg_video_dev label makes no sense: if the video device
is successfully registered, then probe() returns 0. So you never need to
unregister the video device again. You *do* need to release it with
video_device_release().

So this should be a goto rel_vdev.

And the cleanup sequence at the end also fails to call v4l2_m2m_release().

Can you make v4?

Thanks!

	Hans

> +	}
>  
>  	rga->src_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->src_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dma_attrs;
> +	}
> +
>  	rga->dst_mmu_pages =
>  		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> +	if (!rga->dst_mmu_pages) {
> +		ret = -ENOMEM;
> +		goto free_dst_pages;
> +	}
>  
>  	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>  	def_frame.size = def_frame.stride * def_frame.height;
> @@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
>  	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>  	if (ret) {
>  		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
> -		goto rel_vdev;
> +		goto free_pages;
>  	}
>  
>  	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
> @@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> -rel_vdev:
> -	video_device_release(vfd);
> +free_pages:
> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
> +free_dst_pages:
> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);
> +free_dma_attrs:
> +	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
> +		       rga->cmdbuf_phy,
> +		       DMA_ATTR_WRITE_COMBINE);
>  unreg_video_dev:
>  	video_unregister_device(rga->vfd);
> +	video_device_release(vfd);
>  unreg_v4l2_dev:
>  	v4l2_device_unregister(&rga->v4l2_dev);
>  err_put_clk:
> 


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^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
  2019-03-28 14:47           ` Hans Verkuil
@ 2019-03-28 15:00             ` Kangjie Lu
  -1 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-28 15:00 UTC (permalink / raw)
  To: Hans Verkuil
  Cc: pakki001, Jacob chen, Mauro Carvalho Chehab, Heiko Stuebner,
	linux-media, linux-arm-kernel, linux-rockchip, linux-kernel


On 3/28/19 9:47 AM, Hans Verkuil wrote:
> Hi Kangjie,
>
> Unfortunately there are more issues with the cleanup sequence in
> this probe function:
>
> On 3/14/19 6:03 AM, Kangjie Lu wrote:
>> 1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
>> Further uses of their return values lead to NULL pointer
>> dereferences
>>
>> 2. In the error-handling path, video_unregister_device uses
>> "rga->vfd" which has been freed by video_device_release
>>
>> 3. The error handling for v4l2_m2m_init and video_register_device
>> has memory-leak issues
>>
>> The patch fixes the above issues.
>>
>> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
>> ---
>>   drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
>>   1 file changed, 23 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
>> index 5c653287185f..468365ceb99d 100644
>> --- a/drivers/media/platform/rockchip/rga/rga.c
>> +++ b/drivers/media/platform/rockchip/rga/rga.c
>> @@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
>>   	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
>>   					   &rga->cmdbuf_phy, GFP_KERNEL,
>>   					   DMA_ATTR_WRITE_COMBINE);
>> +	if (!rga->cmdbuf_virt) {
>> +		ret = -ENOMEM;
>> +		goto unreg_video_dev;
> Actually, the unreg_video_dev label makes no sense: if the video device
> is successfully registered, then probe() returns 0. So you never need to
> unregister the video device again. You *do* need to release it with
> video_device_release().
>
> So this should be a goto rel_vdev.
>
> And the cleanup sequence at the end also fails to call v4l2_m2m_release().
>
> Can you make v4?


Thanks for the feedback. Will send a v4.


>
> Thanks!
>
> 	Hans
>
>> +	}
>>   
>>   	rga->src_mmu_pages =
>>   		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
>> +	if (!rga->src_mmu_pages) {
>> +		ret = -ENOMEM;
>> +		goto free_dma_attrs;
>> +	}
>> +
>>   	rga->dst_mmu_pages =
>>   		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
>> +	if (!rga->dst_mmu_pages) {
>> +		ret = -ENOMEM;
>> +		goto free_dst_pages;
>> +	}
>>   
>>   	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>>   	def_frame.size = def_frame.stride * def_frame.height;
>> @@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
>>   	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>>   	if (ret) {
>>   		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
>> -		goto rel_vdev;
>> +		goto free_pages;
>>   	}
>>   
>>   	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
>> @@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
>>   
>>   	return 0;
>>   
>> -rel_vdev:
>> -	video_device_release(vfd);
>> +free_pages:
>> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
>> +free_dst_pages:
>> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);
>> +free_dma_attrs:
>> +	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
>> +		       rga->cmdbuf_phy,
>> +		       DMA_ATTR_WRITE_COMBINE);
>>   unreg_video_dev:
>>   	video_unregister_device(rga->vfd);
>> +	video_device_release(vfd);
>>   unreg_v4l2_dev:
>>   	v4l2_device_unregister(&rga->v4l2_dev);
>>   err_put_clk:
>>

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak
@ 2019-03-28 15:00             ` Kangjie Lu
  0 siblings, 0 replies; 16+ messages in thread
From: Kangjie Lu @ 2019-03-28 15:00 UTC (permalink / raw)
  To: Hans Verkuil
  Cc: Heiko Stuebner, Jacob chen, linux-kernel, linux-rockchip,
	pakki001, Mauro Carvalho Chehab, linux-arm-kernel, linux-media


On 3/28/19 9:47 AM, Hans Verkuil wrote:
> Hi Kangjie,
>
> Unfortunately there are more issues with the cleanup sequence in
> this probe function:
>
> On 3/14/19 6:03 AM, Kangjie Lu wrote:
>> 1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
>> Further uses of their return values lead to NULL pointer
>> dereferences
>>
>> 2. In the error-handling path, video_unregister_device uses
>> "rga->vfd" which has been freed by video_device_release
>>
>> 3. The error handling for v4l2_m2m_init and video_register_device
>> has memory-leak issues
>>
>> The patch fixes the above issues.
>>
>> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
>> ---
>>   drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
>>   1 file changed, 23 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
>> index 5c653287185f..468365ceb99d 100644
>> --- a/drivers/media/platform/rockchip/rga/rga.c
>> +++ b/drivers/media/platform/rockchip/rga/rga.c
>> @@ -889,11 +889,24 @@ static int rga_probe(struct platform_device *pdev)
>>   	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
>>   					   &rga->cmdbuf_phy, GFP_KERNEL,
>>   					   DMA_ATTR_WRITE_COMBINE);
>> +	if (!rga->cmdbuf_virt) {
>> +		ret = -ENOMEM;
>> +		goto unreg_video_dev;
> Actually, the unreg_video_dev label makes no sense: if the video device
> is successfully registered, then probe() returns 0. So you never need to
> unregister the video device again. You *do* need to release it with
> video_device_release().
>
> So this should be a goto rel_vdev.
>
> And the cleanup sequence at the end also fails to call v4l2_m2m_release().
>
> Can you make v4?


Thanks for the feedback. Will send a v4.


>
> Thanks!
>
> 	Hans
>
>> +	}
>>   
>>   	rga->src_mmu_pages =
>>   		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
>> +	if (!rga->src_mmu_pages) {
>> +		ret = -ENOMEM;
>> +		goto free_dma_attrs;
>> +	}
>> +
>>   	rga->dst_mmu_pages =
>>   		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
>> +	if (!rga->dst_mmu_pages) {
>> +		ret = -ENOMEM;
>> +		goto free_dst_pages;
>> +	}
>>   
>>   	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
>>   	def_frame.size = def_frame.stride * def_frame.height;
>> @@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
>>   	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
>>   	if (ret) {
>>   		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
>> -		goto rel_vdev;
>> +		goto free_pages;
>>   	}
>>   
>>   	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
>> @@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
>>   
>>   	return 0;
>>   
>> -rel_vdev:
>> -	video_device_release(vfd);
>> +free_pages:
>> +	free_pages((unsigned long)rga->src_mmu_pages, 3);
>> +free_dst_pages:
>> +	free_pages((unsigned long)rga->dst_mmu_pages, 3);
>> +free_dma_attrs:
>> +	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
>> +		       rga->cmdbuf_phy,
>> +		       DMA_ATTR_WRITE_COMBINE);
>>   unreg_video_dev:
>>   	video_unregister_device(rga->vfd);
>> +	video_device_release(vfd);
>>   unreg_v4l2_dev:
>>   	v4l2_device_unregister(&rga->v4l2_dev);
>>   err_put_clk:
>>

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^ permalink raw reply	[flat|nested] 16+ messages in thread

end of thread, other threads:[~2019-03-28 15:01 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-09  6:35 [PATCH] media: rga: fix NULL pointer dereferences Kangjie Lu
2019-03-09  6:35 ` Kangjie Lu
2019-03-11 13:15 ` Steven Price
2019-03-11 13:15   ` Steven Price
2019-03-12  6:58   ` [PATCH v2] media: rga: fix NULL pointer dereferences and a memory leak Kangjie Lu
2019-03-12  6:58     ` Kangjie Lu
2019-03-13 13:35     ` Steven Price
2019-03-13 13:35       ` Steven Price
2019-03-14  5:03       ` [PATCH v3] media: rga: fix NULL pointer dereferences, use-after-free, " Kangjie Lu
2019-03-14  5:03         ` Kangjie Lu
2019-03-14 10:30         ` Steven Price
2019-03-14 10:30           ` Steven Price
2019-03-28 14:47         ` Hans Verkuil
2019-03-28 14:47           ` Hans Verkuil
2019-03-28 15:00           ` Kangjie Lu
2019-03-28 15:00             ` Kangjie Lu

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