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>
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 652ca18..b066786 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -555,6 +555,7 @@
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 @@
{
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 @@
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 @@
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 @@
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 = {
