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 95AF9C05027 for ; Sun, 29 Jan 2023 21:49:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232818AbjA2Vtm (ORCPT ); Sun, 29 Jan 2023 16:49:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229617AbjA2Vtm (ORCPT ); Sun, 29 Jan 2023 16:49:42 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71767193DE for ; Sun, 29 Jan 2023 13:49:41 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0C01960E0B for ; Sun, 29 Jan 2023 21:49:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 54D03C433EF; Sun, 29 Jan 2023 21:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1675028980; bh=6IUUlE0fmtirQhZxPCqbLGa7eHWi10z9YGAy6Bj/E78=; h=Date:To:From:Subject:From; b=nIj5Q3ZwWSn1Iq7Doe++W5faUJ5kooAKTdO71afWVvSRbAUEzw66fBsVOtvYx1JPK 8s/365AQ+ZDgKoPEwCK4ZJosdgVHxwLr7DQIeaiNy6E8FbZhvTmoR99A6MhmW/eu9P +DXYBLEnNz6eGAlnuhwvBTEa25kJVPYGibhGulJU= Date: Sun, 29 Jan 2023 13:49:39 -0800 To: mm-commits@vger.kernel.org, tj@kernel.org, shakeelb@google.com, naoya.horiguchi@nec.com, mhocko@suse.com, mawupeng1@huawei.com, jack@suse.cz, axboe@kernel.dk, wangkefeng.wang@huawei.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-memcg-fix-null-pointer-in-mem_cgroup_track_foreign_dirty_slowpath.patch added to mm-hotfixes-unstable branch Message-Id: <20230129214940.54D03C433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: memcg: fix NULL pointer in mem_cgroup_track_foreign_dirty_slowpath() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-memcg-fix-null-pointer-in-mem_cgroup_track_foreign_dirty_slowpath.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memcg-fix-null-pointer-in-mem_cgroup_track_foreign_dirty_slowpath.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Kefeng Wang Subject: mm: memcg: fix NULL pointer in mem_cgroup_track_foreign_dirty_slowpath() Date: Sun, 29 Jan 2023 12:09:45 +0800 As commit 18365225f044 ("hwpoison, memcg: forcibly uncharge LRU pages"), hwpoison will forcibly uncharg a LRU hwpoisoned page, the folio_memcg could be NULl, then, mem_cgroup_track_foreign_dirty_slowpath() could occurs a NULL pointer dereference, let's do not record the foreign writebacks for folio memcg is null in mem_cgroup_track_foreign_dirty() to fix it. Link: https://lkml.kernel.org/r/20230129040945.180629-1-wangkefeng.wang@huawei.com Fixes: 97b27821b485 ("writeback, memcg: Implement foreign dirty flushing") Signed-off-by: Kefeng Wang Reported-by: Ma Wupeng Cc: Jan Kara Cc: Jens Axboe Cc: Kefeng Wang Cc: Ma Wupeng Cc: Naoya Horiguchi Cc: Shakeel Butt Cc: Tejun Heo Cc: Michal Hocko Signed-off-by: Andrew Morton --- --- a/include/linux/memcontrol.h~mm-memcg-fix-null-pointer-in-mem_cgroup_track_foreign_dirty_slowpath +++ a/include/linux/memcontrol.h @@ -1666,10 +1666,13 @@ void mem_cgroup_track_foreign_dirty_slow static inline void mem_cgroup_track_foreign_dirty(struct folio *folio, struct bdi_writeback *wb) { + struct mem_cgroup *memcg; + if (mem_cgroup_disabled()) return; - if (unlikely(&folio_memcg(folio)->css != wb->memcg_css)) + memcg = folio_memcg(folio); + if (unlikely(memcg && &memcg->css != wb->memcg_css)) mem_cgroup_track_foreign_dirty_slowpath(folio, wb); } _ Patches currently in -mm which might be from wangkefeng.wang@huawei.com are mm-hwposion-support-recovery-from-ksm_might_need_to_copy.patch mm-hwposion-support-recovery-from-ksm_might_need_to_copy-v3.patch mm-memcg-fix-null-pointer-in-mem_cgroup_track_foreign_dirty_slowpath.patch mm-madvise-use-vm_normal_folio-in-madvise_free_pte_range.patch