From patchwork Mon Jul 17 18:47:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13316293 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 79AB9EB64DC for ; Mon, 17 Jul 2023 18:47:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229759AbjGQSrX (ORCPT ); Mon, 17 Jul 2023 14:47:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230161AbjGQSrW (ORCPT ); Mon, 17 Jul 2023 14:47:22 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3703C9D; Mon, 17 Jul 2023 11:47:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689619641; x=1721155641; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=Xn4mhx8wb+pDDvuBnsfj8E37sdsIB+VR4lYH55ZoQHk=; b=T+s9ij9NaN7rOESMeFL11IgEPCXS5O69U+dy7O0cf3sozFqxR8E3Oa7S TkUub/d9iZnwfqxvjwk6Q0oMbXUnar9RvmWG5wQay7jSWjjl0tBwFKaYg +HOZeFF/S5ZcNtFTiX1hM6C/p+LyylYe669vYFdBFlgmmAosGbDfpy2RO kjRlrtGuqTqruLt4JwMw24mRBQoFVx5R8f71k284zOAkGNeMGKX8CP5g/ LsnQigBEHIAPxwqhA+blK/bgbAVSgBstTkJkZauvIecFAHt8SjgxkpGaZ JhkA61eUc+a21itcc6AH4D2mgoLWvc8nV4JcfRSvk8PCuD5HrPpUF90lw g==; X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="429771528" X-IronPort-AV: E=Sophos;i="6.01,211,1684825200"; d="scan'208";a="429771528" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2023 11:47:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="1053987123" X-IronPort-AV: E=Sophos;i="6.01,211,1684825200"; d="scan'208";a="1053987123" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by fmsmga005.fm.intel.com with ESMTP; 17 Jul 2023 11:47:19 -0700 From: Haitao Huang To: jarkko@kernel.org, dave.hansen@linux.intel.com, tj@kernel.org, linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, cgroups@vger.kernel.org, Zefan Li , Johannes Weiner Cc: vipinsh@google.com, kai.huang@intel.com, reinette.chatre@intel.com, zhiquan1.li@intel.com, kristen@linux.intel.com Subject: [PATCH] cgroup/misc: Fix an overflow Date: Mon, 17 Jul 2023 11:47:19 -0700 Message-Id: <20230717184719.85523-1-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org The variable 'new_usage' in misc_cg_try_charge() may overflow if it becomes above INT_MAX. This was observed when I implement the new SGX EPC cgroup[1] as a misc cgroup and test on a platform with large SGX EPC sizes. Change type of new_usage to long from int and check overflow. Fixes: a72232eabdfcf ("cgroup: Add misc cgroup controller") Signed-off-by: Haitao Huang [1] https://lore.kernel.org/linux-sgx/20230712230202.47929-1-haitao.huang@linux.intel.com/ --- kernel/cgroup/misc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c index fe3e8a0eb7ed..ff9f900981a3 100644 --- a/kernel/cgroup/misc.c +++ b/kernel/cgroup/misc.c @@ -143,7 +143,7 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, struct misc_cg *i, *j; int ret; struct misc_res *res; - int new_usage; + long new_usage; if (!(valid_type(type) && cg && READ_ONCE(misc_res_capacity[type]))) return -EINVAL; @@ -153,10 +153,10 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, for (i = cg; i; i = parent_misc(i)) { res = &i->res[type]; - new_usage = atomic_long_add_return(amount, &res->usage); if (new_usage > READ_ONCE(res->max) || - new_usage > READ_ONCE(misc_res_capacity[type])) { + new_usage > READ_ONCE(misc_res_capacity[type]) || + new_usage < 0) { ret = -EBUSY; goto err_charge; }