[PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

Error handling code following kmalloc should free the allocated data.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
---
 drivers/media/video/uvc/uvc_video.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 5b757f3..ce2c484 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -128,8 +128,11 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 	if (data == NULL)
 		return -ENOMEM;
 
-	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
-		return -EIO;
+	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
+			query == UVC_GET_DEF) {
+		ret = -EIO;
+		goto out;
+	}
 
 	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
 		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,

Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Laurent Pinchart]

On Friday 11 September 2009 18:21:18 Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Error handling code following kmalloc should free the allocated data.
> 
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,f1,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
> 
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
>      when != if (...) { <+...x...+> }
> (
> x->f1 = E
> 
>  (x->f1 == NULL || ...)
> 
>  f(...,x->f1,...)
> )
> ...>
> (
>  return \(0\|<+...x...+>\|ptr\);
> 
>  return@p2 ...;
> )
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> print "* file: %s kmalloc %s return %s" %
>  (p1[0].file,p1[0].line,p2[0].line) // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> ---
>  drivers/media/video/uvc/uvc_video.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/video/uvc/uvc_video.c
>  b/drivers/media/video/uvc/uvc_video.c index 5b757f3..ce2c484 100644
> --- a/drivers/media/video/uvc/uvc_video.c
> +++ b/drivers/media/video/uvc/uvc_video.c
> @@ -128,8 +128,11 @@ static int uvc_get_video_ctrl(struct uvc_streaming
>  *stream, if (data == NULL)
>  		return -ENOMEM;
> 
> -	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
> -		return -EIO;
> +	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
> +			query == UVC_GET_DEF) {
> +		ret = -EIO;
> +		goto out;
> +	}

This check can be moved before kmalloc(), removing the need to free memory in 
case of error.

Julia, do you want to submit a modified patch or should I do it myself ?
 
>  	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
>  		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
> 

-- 
Regards,

Laurent Pinchart

Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Julia Lawall]

> > -	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
> > -		return -EIO;
> > +	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
> > +			query == UVC_GET_DEF) {
> > +		ret = -EIO;
> > +		goto out;
> > +	}
> 
> This check can be moved before kmalloc(), removing the need to free memory in 
> case of error.
> 
> Julia, do you want to submit a modified patch or should I do it myself ?

I can do it.  I will send a revised patch shortly.

julia

Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

Move the kzalloc and associated test after the stream/query test, to avoid
the need to free the allocated if the stream/query test fails.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
---
 drivers/media/video/uvc/uvc_video.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 5b757f3..f960e8e 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -124,13 +124,14 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 	int ret;
 
 	size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
+			query == UVC_GET_DEF)
+		return -EIO;
+
 	data = kmalloc(size, GFP_KERNEL);
 	if (data == NULL)
 		return -ENOMEM;
 
-	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
-		return -EIO;
-
 	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
 		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
 		size, UVC_CTRL_STREAMING_TIMEOUT);

Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Laurent Pinchart]

Hi Julia,

On Sunday 13 September 2009 22:55:30 Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Move the kzalloc and associated test after the stream/query test, to avoid
> the need to free the allocated if the stream/query test fails.
> 
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,f1,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
> 
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
>      when != if (...) { <+...x...+> }
> (
> x->f1 = E
> 
>  (x->f1 == NULL || ...)
> 
>  f(...,x->f1,...)
> )
> ...>
> (
>  return \(0\|<+...x...+>\|ptr\);
> 
>  return@p2 ...;
> )
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> print "* file: %s kmalloc %s return %s" %
>  (p1[0].file,p1[0].line,p2[0].line) // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> ---
>  drivers/media/video/uvc/uvc_video.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/video/uvc/uvc_video.c
>  b/drivers/media/video/uvc/uvc_video.c index 5b757f3..f960e8e 100644
> --- a/drivers/media/video/uvc/uvc_video.c
> +++ b/drivers/media/video/uvc/uvc_video.c
> @@ -124,13 +124,14 @@ static int uvc_get_video_ctrl(struct uvc_streaming
>  *stream, int ret;
> 
>  	size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
> +	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
> +			query == UVC_GET_DEF)

This fits in the 80 columns limit, no need to split the statement on multiple 
lines.

> +		return -EIO;
> +
>  	data = kmalloc(size, GFP_KERNEL);
>  	if (data == NULL)
>  		return -ENOMEM;
> 
> -	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
> -		return -EIO;
> -
>  	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
>  		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
>  		size, UVC_CTRL_STREAMING_TIMEOUT);

Other than that,

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Laurent Pinchart

Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

Move the kzalloc and associated test after the stream/query test, to avoid
the need to free the allocated if the stream/query test fails.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
---
 drivers/media/video/uvc/uvc_video.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 5b757f3..2f2971a 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -124,13 +124,13 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 	int ret;
 
 	size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
+		return -EIO;
+
 	data = kmalloc(size, GFP_KERNEL);
 	if (data == NULL)
 		return -ENOMEM;
 
-	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
-		return -EIO;
-
 	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
 		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
 		size, UVC_CTRL_STREAMING_TIMEOUT);

Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

[Laurent Pinchart]

On Tuesday 15 September 2009 11:54:36 Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Move the kzalloc and associated test after the stream/query test, to avoid
> the need to free the allocated if the stream/query test fails.
> 
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,f1,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
> 
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
>      when != if (...) { <+...x...+> }
> (
> x->f1 = E
> 
>  (x->f1 == NULL || ...)
> 
>  f(...,x->f1,...)
> )
> ...>
> (
>  return \(0\|<+...x...+>\|ptr\);
> 
>  return@p2 ...;
> )
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> print "* file: %s kmalloc %s return %s" %
>  (p1[0].file,p1[0].line,p2[0].line) // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

I'll apply and submit a pull request.

Thanks for the patch.

> ---
>  drivers/media/video/uvc/uvc_video.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/video/uvc/uvc_video.c
>  b/drivers/media/video/uvc/uvc_video.c index 5b757f3..2f2971a 100644
> --- a/drivers/media/video/uvc/uvc_video.c
> +++ b/drivers/media/video/uvc/uvc_video.c
> @@ -124,13 +124,13 @@ static int uvc_get_video_ctrl(struct uvc_streaming
>  *stream, int ret;
> 
>  	size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
> +	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
> +		return -EIO;
> +
>  	data = kmalloc(size, GFP_KERNEL);
>  	if (data == NULL)
>  		return -ENOMEM;
> 
> -	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
> -		return -EIO;
> -
>  	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
>  		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
>  		size, UVC_CTRL_STREAMING_TIMEOUT);
> 

-- 
Laurent Pinchart