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 80FB33F9F50; Sat, 12 Sep 2026 15:58:17 +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=1789228698; cv=none; b=nB6TGSAZmpdCm8+FFWtfT8R18OXrj4d6ueaAgFmHreeGoXD/utyZRMF/maFTWtONKrJiauQDEtFY829vn6jpYK8MC1HGwFOzG2/PmjUonZnbYhrK7KQaW/jNn+Lb5EJYZ5DiKxW/JojWArzISIQyQ92iyUNQ4fW3g9WJwkmrk+I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789228698; c=relaxed/simple; bh=B1S7SZr9Cdwp7N2QLIDI+GP73P9g1g8jlJeJ9lUkX/4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EOi2VfHCYKKn9njkaWUn7JUzyfdE9BDc13CAyyOLfopM0r3tg4NL730/ukzFJdHaNnshqfAtIaIFyp5sbG1xi2rUDHim1qHliAKwIfvEg22TFIj9NLkun0FAI6PD2bC3s6jhYuoz/AiPsB+0Mh4iAAYHufgIqC3OZjSyfgoP3RA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GFCX4ogd; 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="GFCX4ogd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33D701F00893; Sat, 12 Sep 2026 15:58:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789228697; bh=TALiVRu4BH/p8McwUPqZ1rKzYOyJXaDjs/0y+9yu+z0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GFCX4ogdRA2syGfiBJ04VBUOy/lEv1zjkdkDcN6eCfYGRphALP1jmka0dTqU4jUaT tPCbFfk97rPyb0SuY3k9ZMpTBdsgOULhkVOnMG3kppm5j0doCpY4yJa8fkFRTPseF5 S0jBLjil2lwtWFDyp4jKLRT6O6bFuIGWRZ2sDxN8= 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 6.1 0438/1191] mm/damon/vaddr-kunit: check region count in three_regions test Date: Sat, 12 Sep 2026 08:52:46 +0200 Message-ID: <20260912065558.071993207@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065548.086904252@linuxfoundation.org> References: <20260912065548.086904252@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 6.1-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/vaddr-test.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h index dda3c186ffefe..bed92599e9782 100644 --- a/mm/damon/vaddr-test.h +++ b/mm/damon/vaddr-test.h @@ -141,12 +141,17 @@ 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