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 1E3C142B75D; Fri, 17 Jul 2026 14:34:56 +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=1784298897; cv=none; b=owqbE7a0dJyoe3xlheLtYLMv9OL3gdHZxUQN3DOFxGPU30uxWb7DTErNmW/6Pv+wdovcFMDQZE3sKBVja6IsaAGo7rAvaBLmGLjocjxAeDOKUUVhQrYToiANN6uHaLvaH9wajsqFtxYLos94/ZXK3icX+0sLmttkIgEo03Paf/Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784298897; c=relaxed/simple; bh=zOJUHYSF/SfkTCPWN4DkTs3aKPcsBPC82UqmWEWXMmo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MfqqBMKFNubPDDAjPQCzrHvMJJB56EZ5muJAvpJRNu0qieCUMUUBCIXTtvuPsMRaLLqhkVx6PjhmHyaHXtuFTrp3QPJvsW2usmbNY/X5J0CMZlnOLrtDq7ZoA8RX/GzVLQBeutVnqFyOu6K/kcYJpWVatZzUqXZOECCkFycqYn8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ICVbrfZK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ICVbrfZK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFAEE1F00A3A; Fri, 17 Jul 2026 14:34:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784298896; bh=hlaPqrC6aZ24tUVqmNoMgW7uRiUtt18MWvor7D56nnY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ICVbrfZK6cVoxKsi44Lk4Kn3Gu6CpPdntck4mGTFh7AtJHNjq5PJbquA1SUbvvpjC zeYNGiTp3OLtzdArKhatXEgccYWS3FM53j5VL0enYSv08EWGPfXiihj+W5I//u8lwp j/DAdd+qZyJp0zdgAyyypLGyDFBv/9DaRUzqC3Iog2zT6rkO5eG5JcHg70+VnTm2CG NLpDLqkLRV8BxPP3kMPgfTd0eem0YnEDrwZuKVDoN4bZk/jMNm6W+XiqB0xYXw74mO 4Mj9lF0CzsdGctP0DXaezJsyy1m6/x4JgN+sZy1WBRs2vajYtHZBM96BriXFE9Ur57 XBk4OWMdrOjkg== From: SJ Park To: Cc: SJ Park , stable@vger.kernel.org, Andrew Morton , Brendan Higgins , David Gow , damon@lists.linux.dev, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1.1 7/7] mm/damon/core-kunit: skip wrong region walk in commit_target_regions() Date: Fri, 17 Jul 2026 07:34:44 -0700 Message-ID: <20260717143445.91207-8-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260717143445.91207-1-sj@kernel.org> References: <20260717143445.91207-1-sj@kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit damon_test_commit_target_regions_for() traverses expected values array after damon_commit_target_regions() call. It assumes damon_commit_target_regions() made expected number of regions. It might not. Because the traversal is made based on the region count, it could do out of bounds access to the expectation value array. The consequent user impact (out-of-bound access) 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. [1] https://lore.kernel.org/20260713144757.39740-1-sj@kernel.org Fixes: 603f67eb91e0 ("mm/damon/tests/core-kunit: add damon_commit_target_regions() test") Cc: # 6.19.x Signed-off-by: SJ Park --- mm/damon/tests/core-kunit.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index fbf986aee2dea..4a536d41cdb2d 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -1277,14 +1277,19 @@ static void damon_test_commit_target_regions_for(struct kunit *test, kunit_skip(test, "src target setup fail"); } damon_commit_target_regions(dst_target, src_target, 1); + + KUNIT_EXPECT_EQ(test, damon_nr_regions(dst_target), nr_expect_regions); + if (damon_nr_regions(dst_target) != nr_expect_regions) + goto out; + i = 0; damon_for_each_region(r, dst_target) { KUNIT_EXPECT_EQ(test, r->ar.start, expect_start_end[i][0]); KUNIT_EXPECT_EQ(test, r->ar.end, expect_start_end[i][1]); i++; } - KUNIT_EXPECT_EQ(test, damon_nr_regions(dst_target), nr_expect_regions); - KUNIT_EXPECT_EQ(test, i, nr_expect_regions); + +out: damon_free_target(dst_target); damon_free_target(src_target); } -- 2.47.3