[PATCH] of: unittest: fix memory leak in attach_node_and_children

[PATCH] of: unittest: fix memory leak in attach_node_and_children

[Erhard Furtner]

In attach_node_and_children memory is allocated for full_name via
kasprintf. If the condition of the 1st if is not met the function
returns early without freeing the memory. Add a kfree() to fix that.

Signed-off-by: Erhard Furtner <erhard_f@mailbox.org>
---
 drivers/of/unittest.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 92e895d86458..ca7823eef2b4 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -1146,8 +1146,10 @@ static void attach_node_and_children(struct device_node *np)
 	full_name = kasprintf(GFP_KERNEL, "%pOF", np);
 
 	if (!strcmp(full_name, "/__local_fixups__") ||
-	    !strcmp(full_name, "/__fixups__"))
+	    !strcmp(full_name, "/__fixups__")) {
+		kfree(full_name);
 		return;
+	}
 
 	dup = of_find_node_by_path(full_name);
 	kfree(full_name);
-- 
2.23.0

Re: [PATCH] of: unittest: fix memory leak in attach_node_and_children

[Michael Ellerman]

Erhard Furtner <erhard_f@mailbox.org> writes:
> In attach_node_and_children memory is allocated for full_name via
> kasprintf. If the condition of the 1st if is not met the function
> returns early without freeing the memory. Add a kfree() to fix that.

It would be good to mention that this was detected with kmemleak.

It looks like the leak was introduced by this commit:

Fixes: 5babefb7f7ab ("of: unittest: allow base devicetree to have symbol metadata")

> Signed-off-by: Erhard Furtner <erhard_f@mailbox.org>
> ---
>  drivers/of/unittest.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>


Because this patch is to drivers/of, you need to send it to the right
folks. You can work out who with:

  $ ./scripts/get_maintainer.pl -f drivers/of/unittest.c
  robh+dt@kernel.org
  frowand.list@gmail.com
  devicetree@vger.kernel.org
  linux-kernel@vger.kernel.org


So to get it merged you should send a v2 (ie. with "PATCH v2" in the
subject), and Cc those people above as well as linuxppc-dev.

You should include the Fixes and Reviewed-by tags I've posted above in
your v2.

cheers

> diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> index 92e895d86458..ca7823eef2b4 100644
> --- a/drivers/of/unittest.c
> +++ b/drivers/of/unittest.c
> @@ -1146,8 +1146,10 @@ static void attach_node_and_children(struct device_node *np)
>  	full_name = kasprintf(GFP_KERNEL, "%pOF", np);
>  
>  	if (!strcmp(full_name, "/__local_fixups__") ||
> -	    !strcmp(full_name, "/__fixups__"))
> +	    !strcmp(full_name, "/__fixups__")) {
> +		kfree(full_name);
>  		return;
> +	}
>  
>  	dup = of_find_node_by_path(full_name);
>  	kfree(full_name);
> -- 
> 2.23.0

Re: [PATCH] of: unittest: fix memory leak in attach_node_and_children

[Tyrel Datwyler]

On 11/14/19 10:43 AM, Erhard Furtner wrote:
> In attach_node_and_children memory is allocated for full_name via
> kasprintf. If the condition of the 1st if is not met the function
> returns early without freeing the memory. Add a kfree() to fix that.
> 
> Signed-off-by: Erhard Furtner <erhard_f@mailbox.org>

Michael provided instructions about what needs to be done with a v2 spin of your
patch to get it upstream. Please feel free to include my reviewed-by as well.

Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>

> ---
>  drivers/of/unittest.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> index 92e895d86458..ca7823eef2b4 100644
> --- a/drivers/of/unittest.c
> +++ b/drivers/of/unittest.c
> @@ -1146,8 +1146,10 @@ static void attach_node_and_children(struct device_node *np)
>  	full_name = kasprintf(GFP_KERNEL, "%pOF", np);
> 
>  	if (!strcmp(full_name, "/__local_fixups__") ||
> -	    !strcmp(full_name, "/__fixups__"))
> +	    !strcmp(full_name, "/__fixups__")) {
> +		kfree(full_name);
>  		return;
> +	}
> 
>  	dup = of_find_node_by_path(full_name);
>  	kfree(full_name);
>