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 04AB318B0A; Sat, 18 Jul 2026 00:14:48 +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=1784333689; cv=none; b=MJcMx5orhflxeZLNCwCubILTbYyHYINWseDX40kLYENXan7EpR63L+lo+TaA0M3zi0OGZKBLaoVPtz0DwzW3/OX+z8iWrDC84lfg/i6ewWYRMiA8s29IJCRvUEtFOYz7tYRApAkXAXA9CWBc5TaPz+dEitVxdnllPcGPKA0AWWM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784333689; c=relaxed/simple; bh=zOJUHYSF/SfkTCPWN4DkTs3aKPcsBPC82UqmWEWXMmo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K7XMY9qWo+D88bIXVlBZZ4sXsWvNRQ/q31gH8kiVgMlv0ykD0Gfxc7WimH+bOe0Z2yp1IJdMS+qn3SNqL0vW98cAKIuKlJl197tzVXWS2ZNP+OD11BEhomQKijAKGoDwlslNcR7jGmJx6JhncyMniQBfdKeRbR7Qst3dPjTdvxo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DcZST0Jy; 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="DcZST0Jy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9137D1F00A3A; Sat, 18 Jul 2026 00:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784333687; bh=hlaPqrC6aZ24tUVqmNoMgW7uRiUtt18MWvor7D56nnY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=DcZST0JyZ+VsKqU9PvOID36E9CRrNSLnOGd8EFTWxNPgb/FkFEKw7G8fsXiPmcgtU Aw8pWXa/P+qt01XtysDSejd52LvREX3r51PgldBJAJkTI55yAnH92FgrZ0CkdVMnEb Vu6V6vKTRiMWDLz7evQItMSQZ5WPpAMRxFipilfAbj4fr7j+FmkqR18ef4u5lr6AoU b6fKlaC1YHNFVRf+en/jSKYQRAz6xfr3IJm/QmICHoIjDEfiRK5f1OGbBQy4v3NswL lStie6B8ySy71K8yKxdIn6i2qT1+Ok/VKVQ/N0o0O3PaqT+qtPQLncD3da9gsrxScq UjnGKstrcxxVg== From: SJ Park To: Andrew Morton Cc: SJ Park , stable@vger.kernel.org, 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: [PATCH 7/7] mm/damon/core-kunit: skip wrong region walk in commit_target_regions() Date: Fri, 17 Jul 2026 17:14:41 -0700 Message-ID: <20260718001442.87129-8-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260718001442.87129-1-sj@kernel.org> References: <20260718001442.87129-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org 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