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 552CD544891 for ; Tue, 8 Sep 2026 12:56:12 +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=1788872173; cv=none; b=H+auOb9hL0V+inXLTsnmvQOmj9LYpjeAcpqkv6iXqvHXO1BvKPOjVId8NasklwntjpXA7FCG3H8dSQW43xxlE8JL9kYj3OfFYX3kgfrZLDgMbfEEy3opwpllXQCp/fb6rCMnz/TjHniMyxz63PPBnqWFQCy5Dhl9N0EMbStbHvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788872173; c=relaxed/simple; bh=5ngK5CifS2c4MJxhTkJTLCxy3YIcvXiJs33FKglIrlc=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=St2bbNX36kz9rL9FZivVjPBmzFXwxBqF/PBQyMZrh53Wrh1Ea5pz4lXhDh6dcdwW6Ex7gs3YqxF+rQpW1P7CKb5AaLwcXCDNSccgugiHdQlSgRE7kNIEJQw16OlwGYbK6FYxDGli4Aek+uxNz1qauzVEAUQXkuVUlPYXcYd2jlc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xx5WFzbx; 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="Xx5WFzbx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8050B1F00A3A; Tue, 8 Sep 2026 12:56:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788872172; bh=yG0nMDV1LvcT9d+8F0w34ypm3y5EpTUSUoo4F31mu0E=; h=Subject:To:Cc:From:Date; b=Xx5WFzbxUbfqRk+ktyPLgh5wZSteeJxR64nm+WkrCRig/XEimwKt/05lQ2eaGdqdv ykvh/ljFbR18+5nLQzMKyu5qrqUPzYYimFL97u8YTAMAQuV6v5qoD5j9XZDint4GHQ pqgPLMVBhlDN7Lc7gnxwoCOhZvxY8DSyYbjauAkc= Subject: FAILED: patch "[PATCH] mm/damon/tests/core-kunit: catch test failure in" failed to apply to 6.6-stable tree To: sj@kernel.org,akpm@linux-foundation.org,stable@vger.kernel.org Cc: From: Date: Tue, 08 Sep 2026 14:49:08 +0200 Message-ID: <2026090808-subscript-extortion-d6f9@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x b640708929aa956235866bf7717d89018c661083 # git commit -s git send-email --to '' --in-reply-to '2026090808-subscript-extortion-d6f9@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b640708929aa956235866bf7717d89018c661083 Mon Sep 17 00:00:00 2001 From: SJ Park Date: Tue, 14 Jul 2026 20:09:57 -0700 Subject: [PATCH] mm/damon/tests/core-kunit: catch test failure in test_merge_regions_of() 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 diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 485472ddebd1..eba643762132 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -260,11 +260,14 @@ static void damon_test_merge_regions_of(struct kunit *test) damon_merge_regions_of(t, 9, 9999, ctx, true); /* 0-112, 114-130, 130-156, 156-170, 170-230, 230-10170 */ KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 6u); + if (damon_nr_regions(t) != 6) + goto out; for (i = 0; i < 6; 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); damon_destroy_ctx(ctx); }