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 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 EE8DAC33CA1 for ; Tue, 7 Jan 2020 21:00:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C2F94214D8 for ; Tue, 7 Jan 2020 21:00:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430829; bh=fJU2AaaiNHWTUyQlnJtXoLh8qVbNdgfozRG6zEmj3jg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wPHoL/idpVOWj2n80IyJ+2dgJicVayzokuL30K3rUxg3zkCYqSkDc9MZcyGxI/05S Vtx7CKsQFfT501QFMafXpSAWRAOA4m6Sh/eyPjUap2VRyXDo4HTRoHlPN2tM2GtnCE SrEUB+Zfd2bG9MuBhqiOrmEpSlVRyMwQwN3Pmbi8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728280AbgAGVA2 (ORCPT ); Tue, 7 Jan 2020 16:00:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:35252 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727913AbgAGVA1 (ORCPT ); Tue, 7 Jan 2020 16:00:27 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 727E32187F; Tue, 7 Jan 2020 21:00:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430826; bh=fJU2AaaiNHWTUyQlnJtXoLh8qVbNdgfozRG6zEmj3jg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zI+AFSTgQWA77OeOQeuMedN81sdvEBHbf405qTcDwhNq8s3qGZyY6OFhCQ75LTLyR lGP2jfvhIeAjaHo8OfUNtWHeOKcoUHKL6dwO9HkXCCZuSKYW1EqFi7emCwxJgoycZY ho2KQj20Udygv8ze5gvAAecM363hIZQeLJwKVasM= 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 5.4 085/191] memcg: account security cred as well to kmemcg Date: Tue, 7 Jan 2020 21:53:25 +0100 Message-Id: <20200107205337.548140723@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205332.984228665@linuxfoundation.org> References: <20200107205332.984228665@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -223,7 +223,7 @@ 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; @@ -282,7 +282,7 @@ 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; @@ -715,7 +715,7 @@ 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);