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=-3.8 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 autolearn=no 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 59C7CC2D0E8 for ; Sun, 29 Mar 2020 02:17:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1CA502071B for ; Sun, 29 Mar 2020 02:17:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="0DmVsxJW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CA502071B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C23B48E0007; Sat, 28 Mar 2020 22:17:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BAC6B8E0001; Sat, 28 Mar 2020 22:17:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4F5C8E0007; Sat, 28 Mar 2020 22:17:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0140.hostedemail.com [216.40.44.140]) by kanga.kvack.org (Postfix) with ESMTP id 8E7928E0001 for ; Sat, 28 Mar 2020 22:17:24 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 44BD84DA9 for ; Sun, 29 Mar 2020 02:17:24 +0000 (UTC) X-FDA: 76646788008.20.trick30_2380b06a8b846 X-HE-Tag: trick30_2380b06a8b846 X-Filterd-Recvd-Size: 3103 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Sun, 29 Mar 2020 02:17:23 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 C5D99206E6; Sun, 29 Mar 2020 02:17:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585448243; bh=P/V6Gv+0BX1tqhGRfhFP18echUOw+ifm+YrXGtHueX8=; h=Date:From:To:Subject:In-Reply-To:From; b=0DmVsxJWHJV3wjjkeohRVynm7MLX4CDmyzhC0YRO7BvMP7RLlVSpLPbM+DCjTakt8 1HnXthbXPw3GdRLJC+273BRG6tofmsBmxaBRfOpEDKlPLWb347VKl2lclX08PSVcE2 vQj/MUyNsPiwigV7/UDeM0A1e8jJPWDc12rGJ4Q8= Date: Sat, 28 Mar 2020 19:17:22 -0700 From: Andrew Morton To: akpm@linux-foundation.org, almasrymina@google.com, gscrivan@redhat.com, linux-mm@kvack.org, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, rientjes@google.com, tj@kernel.org, torvalds@linux-foundation.org Subject: [patch 3/5] hugetlb_cgroup: fix illegal access to memory Message-ID: <20200329021722.W_psAYHe4%akpm@linux-foundation.org> In-Reply-To: <20200328191456.4fc0b9ca86780f26c122399e@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Mina Almasry Subject: hugetlb_cgroup: fix illegal access to memory This appears to be a mistake in commit faced7e0806cf ("mm: hugetlb controller for cgroups v2"). Essentially that commit does a hugetlb_cgroup_from_counter assuming that page_counter_try_charge has initialized counter, but if page_counter_try_charge has failed then it seems it does not initialize counter, so hugetlb_cgroup_from_counter(counter) ends up pointing to random memory, causing kasan to complain. Solution, simply use h_cg, instead of hugetlb_cgroup_from_counter(counter), since that is a reference to the hugetlb_cgroup anyway. After this change kasan ceases to complain. Link: http://lkml.kernel.org/r/20200313223920.124230-1-almasrymina@google.com Fixes: faced7e0806cf ("mm: hugetlb controller for cgroups v2") Signed-off-by: Mina Almasry Reported-by: syzbot+cac0c4e204952cf449b1@syzkaller.appspotmail.com Acked-by: Giuseppe Scrivano Acked-by: Tejun Heo Cc: Mike Kravetz Cc: David Rientjes Signed-off-by: Andrew Morton --- mm/hugetlb_cgroup.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/hugetlb_cgroup.c~hugetlb_cgroup-fix-illegal-access-to-memory +++ a/mm/hugetlb_cgroup.c @@ -240,8 +240,7 @@ again: if (!page_counter_try_charge(&h_cg->hugepage[idx], nr_pages, &counter)) { ret = -ENOMEM; - hugetlb_event(hugetlb_cgroup_from_counter(counter, idx), idx, - HUGETLB_MAX); + hugetlb_event(h_cg, idx, HUGETLB_MAX); } css_put(&h_cg->css); done: _