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 964C047A0C3; Sat, 12 Sep 2026 11:57:54 +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=1789214275; cv=none; b=DnzTKWNcdWHZGcPM8KkkL9+DPeID+3HcSKOX4Slmfz4vMgi8xnF16gGE9Yo4a7Dvmov/v8A6InMeSnUggTqjhQWMq5iNlfm8JZ8N6XiNWkIe7E6IdXfKXovnquvjxTcYXPbAT8V0GyMNChMSGlgACJBfkMSck4zZ1rvtpx844qQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789214275; c=relaxed/simple; bh=zR43aP+c4RHKpQ88ZCCQY0lnqFJfKJf+WmLnA6o7RE0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YsadmkH4m08v9hltPmgU8UQVtsifIBOgX8zBXeNsOg6he/+kURPtbv1ptE8sQFL3EcktUoGG6PFjdVzwiUjGb3a+7/YVQXp9Rn8eHDTiKQa3sbYV/22DJICMCQyjjZ2LNLPqvzcylng7u8d8eI0sVDXy3THdyQU9+KjTsjIROaQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=x5U+dzQy; 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="x5U+dzQy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 878E91F000FF; Sat, 12 Sep 2026 11:57:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789214274; bh=XBXBpsSoi2MQqOfCcPUlKIXC+jQjQOsZlFDPGaDH7cA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=x5U+dzQySWQAq8YsIPKvmwNd0IVDW5H6cMiw5wgEE8T58haiNiWL5RDdbc8QhS/r4 1k3dxKpvb/YFRimv1BL4J+nI2IHyh+8M6buiX5A95D7rmlvvDY/mMLnRP13BlZOvms e9dG/hMADeGlk0vSYm4awZTI0hT/NzQUJQ2Yvf9g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, SJ Park , Brendan Higgins , Andrew Morton , Sasha Levin Subject: [PATCH 6.12 0294/1376] mm/damon/vaddr-kunit: check region count in three_regions test Date: Sat, 12 Sep 2026 08:45:20 +0200 Message-ID: <20260912065614.101799762@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: stable@vger.kernel.org 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 5fea07e460874c8c7cf00f728efbe22abc62c8d8 ] damon_do_test_apply_three_regions() iterates regions after damon_set_regions() call assuming the function would succeed at setting the number of regions the same to the expected one. It might have failed. In this case, __nth_region_of() in the iteration could return NULL and NULL dereference can happen in the test. The consequent user impact (NULL dereference) is quite bad. The realistic user impact would be limited, though. It would affect only test run setups. Fix it by testing if the number of regions was also changed as expected and exit early for the failure. The issue was discovered [1] by Sashiko. Link: https://lore.kernel.org/20260718001442.87129-4-sj@kernel.org Link: https://lore.kernel.org/20260713144757.39740-1-sj@kernel.org [1] Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: SJ Park Cc: Brendan Higgins Cc: # 5.15.x Signed-off-by: Andrew Morton Signed-off-by: SJ Park Signed-off-by: Sasha Levin --- mm/damon/tests/vaddr-kunit.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/damon/tests/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h index ed2845d9f9a95..9eead9882dcce 100644 --- a/mm/damon/tests/vaddr-kunit.h +++ b/mm/damon/tests/vaddr-kunit.h @@ -149,12 +149,17 @@ static void damon_do_test_apply_three_regions(struct kunit *test, damon_set_regions(t, three_regions, 3); + KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_expected / 2); + if (damon_nr_regions(t) != nr_expected / 2) + goto out; + for (i = 0; i < nr_expected / 2; i++) { r = __nth_region_of(t, i); KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]); KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]); } +out: damon_destroy_target(t); } -- 2.53.0