Re: [PATCH] acer-wmi: fix memory leaks in WMID_set_capabilities and get_wmid_devices

From: Carlos Corbacho
Date: Tue Jul 06 2010 - 03:23:00 EST


On Tuesday 06 July 2010 03:55:36 Axel Lin wrote:
> When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
> the caller must kfree the returned buffer if AE_OK is returned.
>
> The callers of wmi_query_block() pass ACPI_ALLOCATE_BUFFER,
> and thus must check its return value before accessing
> or kfree() on the buffer.
>
> This patch adds a missing kfree(out.pointer) before exit
> WMID_set_capabilities() and get_wmid_devices().
>
> Signed-off-by: Axel Lin <axel.lin@xxxxxxxxx>

Acked-by: Carlos Corbacho <carlos@xxxxxxxxxxxxxxxxxxx>

> ---
> drivers/platform/x86/acer-wmi.c | 10 +++++++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/x86/acer-wmi.c
> b/drivers/platform/x86/acer-wmi.c index 1ea6c43..fe644c6 100644
> --- a/drivers/platform/x86/acer-wmi.c
> +++ b/drivers/platform/x86/acer-wmi.c
> @@ -772,6 +772,7 @@ static acpi_status WMID_set_capabilities(void)
> obj->buffer.length == sizeof(u32)) {
> devices = *((u32 *) obj->buffer.pointer);
> } else {
> + kfree(out.pointer);
> return AE_ERROR;
> }
>
> @@ -788,6 +789,7 @@ static acpi_status WMID_set_capabilities(void)
> if (!(devices & 0x20))
> max_brightness = 0x9;
>
> + kfree(out.pointer);
> return status;
> }
>
> @@ -1095,6 +1097,7 @@ static u32 get_wmid_devices(void)
> struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
> union acpi_object *obj;
> acpi_status status;
> + u32 devices = 0;
>
> status = wmi_query_block(WMID_GUID2, 1, &out);
> if (ACPI_FAILURE(status))
> @@ -1103,10 +1106,11 @@ static u32 get_wmid_devices(void)
> obj = (union acpi_object *) out.pointer;
> if (obj && obj->type == ACPI_TYPE_BUFFER &&
> obj->buffer.length == sizeof(u32)) {
> - return *((u32 *) obj->buffer.pointer);
> - } else {
> - return 0;
> + devices = *((u32 *) obj->buffer.pointer);
> }
> +
> + kfree(out.pointer);
> + return devices;
> }
>
> /*

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