From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EFFA34502A; Sun, 14 Sep 2025 03:33:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757820835; cv=none; b=Rw5/BNzs5upRJ8Zj9eDSZR8wPfZ6oAZJWVNGYi4LsNCTX3+yFzoIlwql5C85YSAZguzGcwBWfHvlYJzIOPbWtsmaMYpIvg06MREvYloP48vb0rkay2lXqZQMf/7kcQ5xnaL5VlFj3ItioZfhmx+1JchqhP4IkP5t4lK44rZ/A0g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757820835; c=relaxed/simple; bh=C7uDg4mWAymr0VhMJyfYAgxltCUj6zFpE1frXnGWO4s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IjRh0ENhRgqSsmVnVV7Lbb/gKZSfVy0bpP7KOscmXNM7DUY9+Impo8/+Q6qLJ7y2bO/XbQwkhvrfT/Z2as37G77A1T2NPjMj7eVHmPSpQswmFhe5gBX7NIFny4VGjfJzaFHQFrnLtqxpixuFGLt7OT254fE/xlvS80YD9bCSAG4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SYiudA3W; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SYiudA3W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D6A9C4CEF1; Sun, 14 Sep 2025 03:33:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757820834; bh=C7uDg4mWAymr0VhMJyfYAgxltCUj6zFpE1frXnGWO4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SYiudA3WD1QwX2tWliFa11eSrFIe8MqR7ceZ44fgWFNVT+HZVxd+3uVinX4ebFSxO nrj9Fjm9Ht52jWxfs3wIH7AaFq99AEcUK/x/G+i7buTisidsJv8vjEoIVjyUyjhimc YVSqJbpCyhT8P9B9FKdsehgs+NofrqMXSEBs0rJHRso9B98cT7yjLEKpWqor9JiHeW dkn5WaNvTWCjosyg+ZBIw0iIN4Asifey8uSdZbQLZ9nDWSYx+12B0C55G8NEWcknfM P7UPkXAJ6UrpMJNVnNBDRNumXFcdLSU6jlRnpO0TM7db16O7g/OoJ+LguUZMWHE69Z voJZyTQ6tbu/A== From: SeongJae Park To: stable@vger.kernel.org Cc: damon@lists.linux.dev, Quanmin Yan , SeongJae Park , Kefeng Wang , ze zuo , Andrew Morton Subject: [PATCH 6.6.y] mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters() Date: Sat, 13 Sep 2025 20:33:50 -0700 Message-Id: <20250914033350.2284-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <2025091317-snowsuit-earthen-6ad7@gregkh> References: <2025091317-snowsuit-earthen-6ad7@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Quanmin Yan Patch series "mm/damon: avoid divide-by-zero in DAMON module's parameters application". DAMON's RECLAIM and LRU_SORT modules perform no validation on user-configured parameters during application, which may lead to division-by-zero errors. Avoid the divide-by-zero by adding validation checks when DAMON modules attempt to apply the parameters. This patch (of 2): During the calculation of 'hot_thres' and 'cold_thres', either 'sample_interval' or 'aggr_interval' is used as the divisor, which may lead to division-by-zero errors. Fix it by directly returning -EINVAL when such a case occurs. Additionally, since 'aggr_interval' is already required to be set no smaller than 'sample_interval' in damon_set_attrs(), only the case where 'sample_interval' is zero needs to be checked. Link: https://lkml.kernel.org/r/20250827115858.1186261-2-yanquanmin1@huawei.com Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting") Signed-off-by: Quanmin Yan Reviewed-by: SeongJae Park Cc: Kefeng Wang Cc: ze zuo Cc: [6.0+] Signed-off-by: Andrew Morton (cherry picked from commit 711f19dfd783ffb37ca4324388b9c4cb87e71363) Signed-off-by: SeongJae Park --- mm/damon/lru_sort.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c index 3de2916a65c3..b4032538b22c 100644 --- a/mm/damon/lru_sort.c +++ b/mm/damon/lru_sort.c @@ -203,6 +203,9 @@ static int damon_lru_sort_apply_parameters(void) unsigned int hot_thres, cold_thres; int err = 0; + if (!damon_lru_sort_mon_attrs.sample_interval) + return -EINVAL; + err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs); if (err) return err; -- 2.39.5