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 7DA14373BF2; Sat, 12 Sep 2026 11:58:04 +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=1789214285; cv=none; b=kZO7JjTVdrMvQY2TTcZOmbPwes43CZ5swuA77wZHuaqxy4k3U7GTHyktPt1nZ4u/vimU8xRFPFkbRXFmPVHJ5t7GizJ4Xmnh2XPQBBe4ckoWhv+5FmZ0/bkEo2Sk/FlAQJt3OJmArklfR2nSvWQZzVzCFZmFCe3LJvV25Uk2oG8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789214285; c=relaxed/simple; bh=8uMxIn8bwMnp4akmy7dW+vGwMifYHnldi7ZIXfJW2Vg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SE7OuPODWhRNgMd+ZdUOCAoaAbtyV3M+NHGjQrCLwq9eDmLcC6XI53uGfx4okcIBwo16GFcWYeSZw5fId8MSbteQVfStr2p6s6Qk1kOUkoxWzaOFoSK/ANQZT3ITXFugGkjJU8FgdCGWbaF49thrEZFxJS48gSc3KT6m94uvDeA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dMrVvQBs; 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="dMrVvQBs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3766E1F000FF; Sat, 12 Sep 2026 11:58:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789214284; bh=BYUY6XMYeAPAmd6YdmOHISBaGy/VFfvvEucL25oOQqk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dMrVvQBsLE8Ft0hc3DCWG8WriPQMWqYww4AmKAWh+zmhguyoIPZaOZ1A1otFMYlcu v10dwlrCiuQb8rctmhVVsNW/Ew2aOCiKGvvbbRd1GlO3cn8zDRjT1Hf22j2nrQ1xww POP8A/VGVUw6r3Z87k/5TK2ykWdbabBsPAZSaGm0= 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 6.12 0296/1376] mm/damon/tests/core-kunit: catch test failure in test_merge_regions_of() Date: Sat, 12 Sep 2026 08:45:22 +0200 Message-ID: <20260912065614.146028510@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@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 6.12-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/tests/core-kunit.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 04abee653ca27..1039d2f793b9b 100644 --- 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(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