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 CAC735678C9; Wed, 9 Sep 2026 14:40:52 +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=1788964854; cv=none; b=PpIjxYhQRda64qRrww+Ka6EET5f66lu5OlW6hfx9epB7EOPkAH62eg28xuSs5a87m7zCNVropQx+7RG9rEthSd3TAgvWiOw5yLDImQq9FlW6e89+9cCorNbVwGJLA/Mehrw3riw8dp4QIXxQL1u/x8gEkmA6q+ZjAgyC/Lv7wDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788964854; c=relaxed/simple; bh=qATxjjJDxGW15M31GYIuP77lLzIMzO4b6PdUhE1c/Ns=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xwkcmtu+5HTMsAZlbHeBUmyr9uwcp7fhIfMZIdP2Rqb8pe0rmTzIvXDNGYKeXb6947oE7HQ5jJGBUiy2r36IzI+73ytbINjNIgTJPNYfLWDQ7MWIVcjNo5hN43HV03YsyTp/ZoFadEvqdHZ2v2Whp69yP4o9EEWnmBmkchGzdzU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=m/38W81b; 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="m/38W81b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DB641F00A3A; Wed, 9 Sep 2026 14:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788964852; bh=Dr9wc+7vR8BVoh/7XZrEEkzFg845VuEYczDF3MMsSZw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=m/38W81bJ8ARHj1vnz2qirmYkOp0h1LziXqqYjjT5LVKP6uBQLzVmC5Nwa4MKauNc JwsZK77wmsn7CvpniRK3ueLMPfYBo0Qc4dEdw1PC6WqZ9e0LZbRdpJzaxZ78nCwxZP +GQg/QJx4o2lcgnCdppMxGn0tyyqxQoVBQRnVbws= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, SJ Park , Andrew Morton Subject: [PATCH 6.18 567/583] mm/damon/tests/core-kunit: catch test failure in test_merge_regions_of() Date: Wed, 9 Sep 2026 15:44:12 +0200 Message-ID: <20260909134257.301911836@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909134237.773280130@linuxfoundation.org> References: <20260909134237.773280130@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: SJ Park commit b640708929aa956235866bf7717d89018c661083 upstream. 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: Greg Kroah-Hartman --- mm/damon/tests/core-kunit.h | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -269,11 +269,14 @@ static void damon_test_merge_regions_of( 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); }