From patchwork Sat Jan 11 09:49:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 234191 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 301A7C33C9E for ; Sat, 11 Jan 2020 09:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06D542077C for ; Sat, 11 Jan 2020 09:59:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736779; bh=V+O5gXI50UZr9RiSdJTgPSb6wN43+H/8XMVH3x8sdWY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NYC1YXgbMbSpSi87hR+jRk/nQ0FzvlAN24md6pEgN0tMxAB1RCdQqJTtr4q4s5VDF vJW22dFweJjeOgHDZFSMaI71QHAKA8BcevSXTUeGz667SWSenoAOP6Uww8d4Lm9bqO 5LyjevdjCVKnNLCx+rfpfXi5dphzRmboVZNUHyBA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728949AbgAKJ7i (ORCPT ); Sat, 11 Jan 2020 04:59:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:54432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728768AbgAKJ7i (ORCPT ); Sat, 11 Jan 2020 04:59:38 -0500 Received: from localhost (unknown [62.119.166.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5648D2084D; Sat, 11 Jan 2020 09:59:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736777; bh=V+O5gXI50UZr9RiSdJTgPSb6wN43+H/8XMVH3x8sdWY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iRVMtXJV3OA7FmIhvZq21OPW7DZx4zF4Pz9aVLY41eknF8QZ3DLjtM6kzhfdcFX22 2e0a3xldr6RJPfJACC+SapUMMl5MXdE7mb9az/wESAiiYt477pV90Omouc44/HE8iW XnI2qBcbWAghBDbZYRozFdrun55z8QvPj55gd2fM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shakeel Butt , Chris Down , Roman Gushchin , Michal Hocko , Johannes Weiner , Andrew Morton , Linus Torvalds Subject: [PATCH 4.9 22/91] memcg: account security cred as well to kmemcg Date: Sat, 11 Jan 2020 10:49:15 +0100 Message-Id: <20200111094852.213118498@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094844.748507863@linuxfoundation.org> References: <20200111094844.748507863@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shakeel Butt commit 84029fd04c201a4c7e0b07ba262664900f47c6f5 upstream. The cred_jar kmem_cache is already memcg accounted in the current kernel but cred->security is not. Account cred->security to kmemcg. Recently we saw high root slab usage on our production and on further inspection, we found a buggy application leaking processes. Though that buggy application was contained within its memcg but we observe much more system memory overhead, couple of GiBs, during that period. This overhead can adversely impact the isolation on the system. One source of high overhead we found was cred->security objects, which have a lifetime of at least the life of the process which allocated them. Link: http://lkml.kernel.org/r/20191205223721.40034-1-shakeelb@google.com Signed-off-by: Shakeel Butt Acked-by: Chris Down Reviewed-by: Roman Gushchin Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/cred.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/kernel/cred.c +++ b/kernel/cred.c @@ -219,7 +219,7 @@ struct cred *cred_alloc_blank(void) new->magic = CRED_MAGIC; #endif - if (security_cred_alloc_blank(new, GFP_KERNEL) < 0) + if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0) goto error; return new; @@ -278,7 +278,7 @@ struct cred *prepare_creds(void) new->security = NULL; #endif - if (security_prepare_creds(new, old, GFP_KERNEL) < 0) + if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0) goto error; validate_creds(new); return new; @@ -653,7 +653,7 @@ struct cred *prepare_kernel_cred(struct #ifdef CONFIG_SECURITY new->security = NULL; #endif - if (security_prepare_creds(new, old, GFP_KERNEL) < 0) + if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0) goto error; put_cred(old);