Re: [PATCH] HID: core: fix NULL pointer dereference

[Stefan Agner]

On 29.08.2018 08:22, Gustavo A. R. Silva wrote:
> There is a NULL pointer dereference in case memory resources
> for *parse* are not successfully allocated.
> 
> Fix this by adding a new goto label and make the execution
> path jump to it in case vzalloc() fails.
> 
> Addresses-Coverity-ID: 1473081 ("Dereference after null check")
> Fixes: b2dd9f2e5a8a ("HID: core: fix memory leak on probe")
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Reviewed-by: Stefan Agner <stefan@xxxxxxxx>

--
Stefan

> ---
>  drivers/hid/hid-core.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 4548dae..5bec924 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -1000,7 +1000,7 @@ int hid_open_report(struct hid_device *device)
>  	parser = vzalloc(sizeof(struct hid_parser));
>  	if (!parser) {
>  		ret = -ENOMEM;
> -		goto err;
> +		goto alloc_err;
>  	}
>  
>  	parser->device = device;
> @@ -1049,6 +1049,7 @@ int hid_open_report(struct hid_device *device)
>  	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
>  err:
>  	kfree(parser->collection_stack);
> +alloc_err:
>  	vfree(parser);
>  	hid_close_report(device);
>  	return ret;