From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02FF9C433FE for ; Mon, 14 Nov 2022 18:30:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237021AbiKNSaX (ORCPT ); Mon, 14 Nov 2022 13:30:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236921AbiKNSaS (ORCPT ); Mon, 14 Nov 2022 13:30:18 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 729E625C47 for ; Mon, 14 Nov 2022 10:30:09 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 287A0B81158 for ; Mon, 14 Nov 2022 18:30:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FF7DC433D6; Mon, 14 Nov 2022 18:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668450606; bh=KjLeGyUJTbZpSiKhaAFgRkOpgkH4ndx+JjCuYdxHGcY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bY29PN+CyQgg6/VdgLjSq/jugOiRFtHQw+Xxc1h2PxY+BLAsSfEJ7e2CBv4KzGmfy 9/aoiEiu5ZSpriSJuR0gSVUmS+zYRvGafuYYtqMPEQDS2NhqQ1kwYdncApO+p92FTX stqy0WYhQYHGIR+bGkXrE3FUPMGugEp+sWfx013Sj93aJjNN7z2YCazcoSLdPWMwYs QdyULgUxl+x46SDTihwnGa4I8eGqJGE7esekjFcM5kv73P444WCvBH9nP8vA/qDCO7 rNn+jHctDyZHC5FSnsfooLElEb7u553FDcpbSBpBYlKV87QumPpjh6nmUZjpp5/d6T jXDfBuLGLo+CQ== From: SeongJae Park To: SeongJae Park , Andrew Morton Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH mm-unstable 2/2] mm/damon/sysfs-schemes: skip schemes regions clearing if the scheme directory has removed Date: Mon, 14 Nov 2022 18:29:54 +0000 Message-Id: <20221114182954.4745-3-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221114182954.4745-1-sj@kernel.org> References: <20221114182954.4745-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A DAMON sysfs interface user can start DAMON with a scheme, remove the sysfs directory for the scheme, and then ask clearing of the scheme's tried regions. Because the schemes tried regions clearing logic doesn't aware of the situation, it results in an invalid memory access. Fix the bug by checking if the scheme sysfs directory exists. Fixes: bb9641eb3a3e ("mm/damon/sysfs-schemes: implement DAMOS-tried regions clear command") # mm-unstable Signed-off-by: SeongJae Park --- mm/damon/sysfs-schemes.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index 4df3c99983e8..e6baf55d617d 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1260,6 +1260,10 @@ int damon_sysfs_schemes_clear_regions( damon_for_each_scheme(scheme, ctx) { struct damon_sysfs_scheme *sysfs_scheme; + /* user could removed the scheme sysfs dir */ + if (schemes_idx >= sysfs_schemes->nr) + break; + sysfs_scheme = sysfs_schemes->schemes_arr[schemes_idx++]; damon_sysfs_scheme_regions_rm_dirs( sysfs_scheme->tried_regions); -- 2.25.1