gpu: ion: Fix memory leak of dirty bits

Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion.c

@@ -164,24 +164,20 @@ static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
 		return ERR_PTR(PTR_ERR(table));
 	}
 	buffer->sg_table = table;
-	if (buffer->flags & ION_FLAG_CACHED)
+	if (buffer->flags & ION_FLAG_CACHED) {
 		for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents,
 			    i) {
 			if (sg_dma_len(sg) == PAGE_SIZE)
 				continue;
 			pr_err("%s: cached mappings must have pagewise "
 			       "sg_lists\n", __func__);
-			heap->ops->unmap_dma(heap, buffer);
-			kfree(buffer);
-			return ERR_PTR(-EINVAL);
+			ret = -EINVAL;
+			goto err;
 		}
 
 		ret = ion_buffer_alloc_dirty(buffer);
-	if (ret) {
-		heap->ops->unmap_dma(heap, buffer);
-		heap->ops->free(buffer);
-		kfree(buffer);
-		return ERR_PTR(ret);
+		if (ret)
+			goto err;
 	}
 
 	buffer->dev = dev;
@@ -200,6 +196,12 @@ static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
 		sg_dma_address(sg) = sg_phys(sg);
 	ion_buffer_add(dev, buffer);
 	return buffer;
+
+err:
+	heap->ops->unmap_dma(heap, buffer);
+	heap->ops->free(buffer);
+	kfree(buffer);
+	return ERR_PTR(ret);
 }
 
 static void ion_buffer_destroy(struct kref *kref)
@@ -209,12 +211,13 @@ static void ion_buffer_destroy(struct kref *kref)
 
 	if (WARN_ON(buffer->kmap_cnt > 0))
 		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
-
 	buffer->heap->ops->unmap_dma(buffer->heap, buffer);
 	buffer->heap->ops->free(buffer);
 	mutex_lock(&dev->lock);
 	rb_erase(&buffer->node, &dev->buffers);
 	mutex_unlock(&dev->lock);
+	if (buffer->flags & ION_FLAG_CACHED)
+		kfree(buffer->dirty);
 	kfree(buffer);
 }