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 ECD3EC433F5 for ; Tue, 10 May 2022 04:10:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235939AbiEJEOA (ORCPT ); Tue, 10 May 2022 00:14:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235915AbiEJENd (ORCPT ); Tue, 10 May 2022 00:13:33 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0448120CA6C for ; Mon, 9 May 2022 21:09:36 -0700 (PDT) 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 sin.source.kernel.org (Postfix) with ESMTPS id 3325ACE1BF7 for ; Tue, 10 May 2022 04:09:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8951AC385A6; Tue, 10 May 2022 04:09:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1652155773; bh=iOvGxRiahu5uoh8TBIzrLJk2USLhvElBMWZ4ydzmW5I=; h=Date:To:From:Subject:From; b=gnKPsJGRaWQGxgCexDJAEMIIXAh5AtD6zfizUgPyFIae6sieVUAq4E+dt8mHrvVB4 knTxWeFVQ6RpWtCqCta5S75a/9f/O85wA5uKjS24DJU90v+IgtyUFH9zXt9bnTCSok rbqF2B/VSHaPxW7kqTtPWNaocOIBtGgfUzEV4oEQ= Date: Mon, 09 May 2022 21:09:32 -0700 To: mm-commits@vger.kernel.org, songmuchun@bytedance.com, glider@google.com, elver@google.com, dvyukov@google.com, 42.hyeyoo@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-kfence-reset-pg_slab-and-memcg_data-before-freeing-__kfence_pool.patch removed from -mm tree Message-Id: <20220510040933.8951AC385A6@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool has been removed from the -mm tree. Its filename was mm-kfence-reset-pg_slab-and-memcg_data-before-freeing-__kfence_pool.patch This patch was dropped because it was merged into mm-hotfixes-stable ------------------------------------------------------ From: Hyeonggon Yoo <42.hyeyoo@gmail.com> Subject: mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool When kfence fails to initialize kfence pool, it frees the pool. But it does not reset memcg_data and PG_slab flag. Below is a BUG because of this. Let's fix it by resetting memcg_data and PG_slab flag before free. [ 0.089149] BUG: Bad page state in process swapper/0 pfn:3d8e06 [ 0.089149] page:ffffea46cf638180 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3d8e06 [ 0.089150] memcg:ffffffff94a475d1 [ 0.089150] flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) [ 0.089151] raw: 0017ffffc0000200 ffffea46cf638188 ffffea46cf638188 0000000000000000 [ 0.089152] raw: 0000000000000000 0000000000000000 00000000ffffffff ffffffff94a475d1 [ 0.089152] page dumped because: page still charged to cgroup [ 0.089153] Modules linked in: [ 0.089153] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G B W 5.18.0-rc1+ #965 [ 0.089154] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 0.089154] Call Trace: [ 0.089155] [ 0.089155] dump_stack_lvl+0x49/0x5f [ 0.089157] dump_stack+0x10/0x12 [ 0.089158] bad_page.cold+0x63/0x94 [ 0.089159] check_free_page_bad+0x66/0x70 [ 0.089160] __free_pages_ok+0x423/0x530 [ 0.089161] __free_pages_core+0x8e/0xa0 [ 0.089162] memblock_free_pages+0x10/0x12 [ 0.089164] memblock_free_late+0x8f/0xb9 [ 0.089165] kfence_init+0x68/0x92 [ 0.089166] start_kernel+0x789/0x992 [ 0.089167] x86_64_start_reservations+0x24/0x26 [ 0.089168] x86_64_start_kernel+0xa9/0xaf [ 0.089170] secondary_startup_64_no_verify+0xd5/0xdb [ 0.089171] Link: https://lkml.kernel.org/r/YnPG3pQrqfcgOlVa@hyeyoo Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") Fixes: 8f0b36497303 ("mm: kfence: fix objcgs vector allocation") Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Marco Elver Reviewed-by: Muchun Song Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton --- mm/kfence/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/mm/kfence/core.c~mm-kfence-reset-pg_slab-and-memcg_data-before-freeing-__kfence_pool +++ a/mm/kfence/core.c @@ -621,6 +621,16 @@ static bool __init kfence_init_pool_earl * fails for the first page, and therefore expect addr==__kfence_pool in * most failure cases. */ + for (char *p = (char *)addr; p < __kfence_pool + KFENCE_POOL_SIZE; p += PAGE_SIZE) { + struct slab *slab = virt_to_slab(p); + + if (!slab) + continue; +#ifdef CONFIG_MEMCG + slab->memcg_data = 0; +#endif + __folio_clear_slab(slab_folio(slab)); + } memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool)); __kfence_pool = NULL; return false; _ Patches currently in -mm which might be from 42.hyeyoo@gmail.com are