From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 46AFE32B9B5; Sat, 12 Sep 2026 14:14:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789222454; cv=none; b=fVSwMb6+RXNPZyEL5EybKGeSe2n/jxFAkNrv2ycvsTe1RTBrXHxELYsHAoQF/Lp9jqjrBp5I/kKwfZAFJNYCZRO3uX/Db2Sr6/N+UWDWS/EdSRK6rq8O4/qdHBqi40R5rCpIAVHq7xFlkO5YGnjP/jcsSogI8OscT+JP+atbrvY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789222454; c=relaxed/simple; bh=z6/dSsqwfSx8wO56uH4AqtABfjDrcMPkDH+4OBo98rQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=InxEhs0q9QgMf1bbP8wsDnv5jF5ocZqbJpqXwEdFng/FDVBrhTTqrgj7Lf05z2uQOwjMJhIP49FwuGj6ZNHzLJkENxLtrfuun9sVHWMED7lhwSNGp2wa88tBYkiOusNJEjpBJco5pqY6OYFxb8iOYu+0BRxPfDgb5WcuQjl3dZw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QegdWd2K; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="QegdWd2K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD2491F000FF; Sat, 12 Sep 2026 14:14:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789222451; bh=2D8HzdqIjJuYJ7Tw0KYFcdSmU0YMkSsoUwKo1AmDY+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QegdWd2KpKzt76D7et2y5NY/zDri/ARVuL0+yTBbLqjSDRrKVEq/W25L71PMCaSWy 1T59EK73ZFkoBRBvOKZzv5MY+kZvSFuWgW3ucpbne8VR7YxdeFmcbzf5XwGBOdan2w y9+4ZxUap04Je0GstpRDLX3j8pRGbxnwUEGN79VY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, SJ Park , Andrew Morton , Sasha Levin Subject: [PATCH 6.6 0537/1424] mm/damon/tests/core-kunit: catch test failure in test_merge_regions_of() Date: Sat, 12 Sep 2026 08:49:29 +0200 Message-ID: <20260912065619.326408793@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: SJ Park [ Upstream commit b640708929aa956235866bf7717d89018c661083 ] KUNIT_EXPECT_EQ() does not abort the execution of test code when the expectation is not met. But damon_test_merge_regions_of() code after its initial KUNIT_EXPECT_EQ() call assumes the expectation is met. It does a per-region test with a hard-coded number of regions that is correct only if the expectation was met. As a result, __nth_region_of() could return NULL, and the test code can dereference NULL pointers. Fix the issue by catching the expectation failure and skip the per-region tests. The user impact on realistic setups should be negligible, as it is a unit test. The issue was discovered [1] by Sashiko. Link: https://lore.kernel.org/20260715031002.108504-3-sj@kernel.org Link: https://lore.kernel.org/20260710144937.26981-1-sj@kernel.org [1] Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: SJ Park Cc: # 5.15.x Signed-off-by: Andrew Morton Signed-off-by: SJ Park Signed-off-by: Sasha Levin --- mm/damon/core-test.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h index 53212bcc9eda7..e6c19a23b0806 100644 --- a/mm/damon/core-test.h +++ b/mm/damon/core-test.h @@ -258,11 +258,14 @@ static void damon_test_merge_regions_of(struct kunit *test) damon_merge_regions_of(t, 9, 9999); /* 0-112, 114-130, 130-156, 156-170 */ KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 5u); + if (damon_nr_regions(t) != 5) + goto out; for (i = 0; i < 5; i++) { r = __nth_region_of(t, i); KUNIT_EXPECT_EQ(test, r->ar.start, saddrs[i]); KUNIT_EXPECT_EQ(test, r->ar.end, eaddrs[i]); } +out: damon_free_target(t); } -- 2.53.0