acer-wmi: fix memory leaks in wmab_execute error path

When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER, the caller
must kfree the returned buffer if AE_OK is returned.

Call Trace:
wmab_execute
  -> wmi_evaluate_method
    -> acpi_evaluate_object

Thus if callers of wmab_execute() pass ACPI_ALLOCATE_BUFFER, the return
buffer must be kfreed if wmab_execute return AE_OK.

[akpm@linux-foundation.org: avoid multiple return points, remove unneeded cast, remove unneeded initialisation of `status']
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
This commit is contained in:
Axel Lin 2010-07-20 15:19:53 -07:00 committed by Matthew Garrett
parent 669048639c
commit 7677fbdff1

View file

@ -555,6 +555,7 @@ static acpi_status AMW0_find_mailled(void)
obj->buffer.length == sizeof(struct wmab_ret)) {
ret = *((struct wmab_ret *) obj->buffer.pointer);
} else {
kfree(out.pointer);
return AE_ERROR;
}
@ -570,7 +571,7 @@ static acpi_status AMW0_set_capabilities(void)
{
struct wmab_args args;
struct wmab_ret ret;
acpi_status status = AE_OK;
acpi_status status;
struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *obj;
@ -593,12 +594,13 @@ static acpi_status AMW0_set_capabilities(void)
if (ACPI_FAILURE(status))
return status;
obj = (union acpi_object *) out.pointer;
obj = out.pointer;
if (obj && obj->type == ACPI_TYPE_BUFFER &&
obj->buffer.length == sizeof(struct wmab_ret)) {
ret = *((struct wmab_ret *) obj->buffer.pointer);
} else {
return AE_ERROR;
status = AE_ERROR;
goto out;
}
if (ret.eax & 0x1)
@ -607,23 +609,26 @@ static acpi_status AMW0_set_capabilities(void)
args.ebx = 2 << 8;
args.ebx |= ACER_AMW0_BLUETOOTH_MASK;
/*
* It's ok to use existing buffer for next wmab_execute call.
* But we need to kfree(out.pointer) if next wmab_execute fail.
*/
status = wmab_execute(&args, &out);
if (ACPI_FAILURE(status))
return status;
goto out;
obj = (union acpi_object *) out.pointer;
if (obj && obj->type == ACPI_TYPE_BUFFER
&& obj->buffer.length == sizeof(struct wmab_ret)) {
ret = *((struct wmab_ret *) obj->buffer.pointer);
} else {
return AE_ERROR;
status = AE_ERROR;
goto out;
}
if (ret.eax & 0x1)
interface->capability |= ACER_CAP_BLUETOOTH;
kfree(out.pointer);
/*
* This appears to be safe to enable, since all Wistron based laptops
* appear to use the same EC register for brightness, even if they
@ -632,7 +637,10 @@ static acpi_status AMW0_set_capabilities(void)
if (quirks->brightness >= 0)
interface->capability |= ACER_CAP_BRIGHTNESS;
return AE_OK;
status = AE_OK;
out:
kfree(out.pointer);
return status;
}
static struct wmi_interface AMW0_interface = {