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 6393DEB64D7 for ; Wed, 21 Jun 2023 07:33:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231326AbjFUHdD (ORCPT ); Wed, 21 Jun 2023 03:33:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229470AbjFUHc7 (ORCPT ); Wed, 21 Jun 2023 03:32:59 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E42691988 for ; Wed, 21 Jun 2023 00:32:58 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id A48331F895; Wed, 21 Jun 2023 07:32:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1687332777; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=6gjfb2p19oiPYpe3DSMJrrCJ9yALR0S9IVL68sM6p2A=; b=aF0QiJBKBa9qywvk+4bhKGiE3WKMpPh7yemKSZhtxRe+/PjujnVs3PKLAPl/6H7BXmPOeg 7KWCZbwjHEqBlp6MZMrXIAD+smMEzUCk1A9535nLjCG4pxmGFGliwIzYrLz9kpVWnDeSl4 Sjns/iUpTmgPf8QbgPj03t4gboTWHHc= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 86CD8133E6; Wed, 21 Jun 2023 07:32:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 0o2cHqmnkmSKOwAAMHmgww (envelope-from ); Wed, 21 Jun 2023 07:32:57 +0000 Date: Wed, 21 Jun 2023 09:32:56 +0200 From: Michal Hocko To: junfei fang Cc: andrew.zhu@mediatek.com, colin.peng@mediatek.com, wangbiao3@xiaomi.com, yangjianlong@xiaomi.com, linux-kernel@vger.kernel.org Subject: Re: kasan cgroup user-after-free in get_mem_cgroup_from_mm Message-ID: References: <20230620022120.27448-1-jefexiaomi@xiaomi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 21-06-23 10:18:31, junfei fang wrote: > Thank you for your prompt response. > > We are using kernel-5.15 in our project and cannot change it. It will be hard to get a community support for such a kernel I am afraid. Especially when considering the kernel is heavily tainted > CPU: 0 PID: 6071 Comm: elastic_postChe Tainted: P S WC OE by proprietary, out-of-tree modules, pre-existing warnings that might be related and TAINT_CPU_OUT_OF_SPEC doesn't add much confidence into setup either. > Do you have any suggestions on how to fix this issue? No, not really. From what I can see the report complains about cset associated with the process' mm. I do not recall any specific bug where css would be released prematurely. Maybe somebody else who is more familiar with the cgroup core would know better. Btw. you should be sending the full UAF report after you have CCed LKML. -- Michal Hocko SUSE Labs