RE: [PATCH] cxl: Fix memory leak bug in alloc_mock_res()

From: Dan Williams
Date: Mon Jul 17 2023 - 19:50:05 EST


Chenyuan Mi wrote:
> When gen_pool_alloc_algo() fails, the error handling path
> forgets to free 'res'. It would cause a memory leak bug.
>
> Fix it by add kfree() in error handling path.

Going forward I want to set the policy that any error path resource leaks be
fixed by converting to using __free() and associated helpers.

So in this case it would be:

-- >8 --
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 0e78d8e19895..ea04995fe42c 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -396,7 +396,8 @@ static void depopulate_all_mock_resources(void)

static struct cxl_mock_res *alloc_mock_res(resource_size_t size, int align)
{
- struct cxl_mock_res *res = kzalloc(sizeof(*res), GFP_KERNEL);
+ struct cxl_mock_res *res __free(kfree) =
+ kzalloc(sizeof(*res), GFP_KERNEL);
struct genpool_data_align data = {
.align = align,
};
@@ -416,7 +417,7 @@ static struct cxl_mock_res *alloc_mock_res(resource_size_t size, int align)
list_add(&res->list, &mock_res);
mutex_unlock(&mock_res_lock);

- return res;
+ return_ptr(res);
}

static int populate_cedt(void)