Commit 0b49c7d0 authored by Christian A. Ehrhardt's avatar Christian A. Ehrhardt Committed by Andrew Morton
Browse files

lib: kunit_iov_iter: fix memory leaks 

Use vfree() instead of vunmap() to free the buffer allocated by
iov_kunit_create_buffer() because vunmap() does not honour
VM_MAP_PUT_PAGES.  In order for this to work the page array itself must
not be managed by kunit.

Remove the folio_put() when destroying a folioq.  This is handled by
vfree(), now.

Pointed out by sashiko.dev on a previous iteration of this series.

Tested by running the kunit test 10000 times in a loop.

Link: https://lkml.kernel.org/r/20260326214905.818170-4-lk@c--e.de


Fixes: 2d71340f ("iov_iter: Kunit tests for copying to/from an iterator")
Signed-off-by: default avatarChristian A. Ehrhardt <lk@c--e.de>
Cc: David Howells <dhowells@redhat.com>
Cc: David Gow <davidgow@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 118cf3f5

lib/tests/kunit_iov_iter.c

+8 −6
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static inline u8 pattern(unsigned long x) 


static void iov_kunit_unmap(void *data)

{

	vunmap(data);

	vfree(data);

}



static void *__init iov_kunit_create_buffer(struct kunit *test,
@@ -53,17 +53,22 @@ static void *__init iov_kunit_create_buffer(struct kunit *test, 
	unsigned long got;

	void *buffer;



	pages = kunit_kcalloc(test, npages, sizeof(struct page *), GFP_KERNEL);

	pages = kzalloc_objs(struct page *, npages, GFP_KERNEL);

	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pages);

	*ppages = pages;



	got = alloc_pages_bulk(GFP_KERNEL, npages, pages);

	if (got != npages) {

		release_pages(pages, got);

		kvfree(pages);

		KUNIT_ASSERT_EQ(test, got, npages);

	}



	buffer = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL);

	if (buffer == NULL) {

		release_pages(pages, got);

		kvfree(pages);

	}

        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);



	kunit_add_action_or_reset(test, iov_kunit_unmap, buffer);
@@ -369,9 +374,6 @@ static void iov_kunit_destroy_folioq(void *data) 


	for (folioq = data; folioq; folioq = next) {

		next = folioq->next;

		for (int i = 0; i < folioq_nr_slots(folioq); i++)

			if (folioq_folio(folioq, i))

				folio_put(folioq_folio(folioq, i));

		kfree(folioq);

	}

}