FAILED: patch "[PATCH] mm/damon/tests/vaddr-kunit: handle alloc failures on" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] mm/damon/tests/vaddr-kunit: handle alloc failures on" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 0a63a0e7570b9b2631dfb8d836dc572709dce39e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026010512-stainless-reliance-2417@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0a63a0e7570b9b2631dfb8d836dc572709dce39e Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj@kernel.org>
Date: Sat, 1 Nov 2025 11:20:13 -0700
Subject: [PATCH] mm/damon/tests/vaddr-kunit: handle alloc failures on
 damon_test_split_evenly_succ()

damon_test_split_evenly_succ() is assuming all dynamic memory allocation
in it will succeed.  Those are indeed likely in the real use cases since
those allocations are too small to fail, but theoretically those could
fail.  In the case, inappropriate memory access can happen.  Fix it by
appropriately cleanup pre-allocated memory and skip the execution of the
remaining tests in the failure cases.

Link: https://lkml.kernel.org/r/20251101182021.74868-20-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/tests/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h
index 1b0f21c2e376..30dc5459f1d2 100644
--- a/mm/damon/tests/vaddr-kunit.h
+++ b/mm/damon/tests/vaddr-kunit.h
@@ -284,10 +284,17 @@ static void damon_test_split_evenly_succ(struct kunit *test,
 	unsigned long start, unsigned long end, unsigned int nr_pieces)
 {
 	struct damon_target *t = damon_new_target();
-	struct damon_region *r = damon_new_region(start, end);
+	struct damon_region *r;
 	unsigned long expected_width = (end - start) / nr_pieces;
 	unsigned long i = 0;
 
+	if (!t)
+		kunit_skip(test, "target alloc fail");
+	r = damon_new_region(start, end);
+	if (!r) {
+		damon_free_target(t);
+		kunit_skip(test, "region alloc fail");
+	}
 	damon_add_region(r, t);
 	KUNIT_EXPECT_EQ(test,
 			damon_va_evenly_split_region(t, r, nr_pieces), 0);

[PATCH 6.6.y] mm/damon/tests/vaddr-kunit: handle alloc failures on damon_test_split_evenly_succ()

[SeongJae Park]

damon_test_split_evenly_succ() is assuming all dynamic memory allocation
in it will succeed.  Those are indeed likely in the real use cases since
those allocations are too small to fail, but theoretically those could
fail.  In the case, inappropriate memory access can happen.  Fix it by
appropriately cleanup pre-allocated memory and skip the execution of the
remaining tests in the failure cases.

Link: https://lkml.kernel.org/r/20251101182021.74868-20-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 0a63a0e7570b9b2631dfb8d836dc572709dce39e)
---
 mm/damon/vaddr-test.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
index b4fc21ef3c70..9813002a981c 100644
--- a/mm/damon/vaddr-test.h
+++ b/mm/damon/vaddr-test.h
@@ -269,10 +269,17 @@ static void damon_test_split_evenly_succ(struct kunit *test,
 	unsigned long start, unsigned long end, unsigned int nr_pieces)
 {
 	struct damon_target *t = damon_new_target();
-	struct damon_region *r = damon_new_region(start, end);
+	struct damon_region *r;
 	unsigned long expected_width = (end - start) / nr_pieces;
 	unsigned long i = 0;
 
+	if (!t)
+		kunit_skip(test, "target alloc fail");
+	r = damon_new_region(start, end);
+	if (!r) {
+		damon_free_target(t);
+		kunit_skip(test, "region alloc fail");
+	}
 	damon_add_region(r, t);
 	KUNIT_EXPECT_EQ(test,
 			damon_va_evenly_split_region(t, r, nr_pieces), 0);
-- 
2.47.3