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 3BB50C433EF for ; Mon, 16 May 2022 20:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348298AbiEPUgD (ORCPT ); Mon, 16 May 2022 16:36:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351115AbiEPUCC (ORCPT ); Mon, 16 May 2022 16:02:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B66ECE0; Mon, 16 May 2022 12:59:11 -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 ams.source.kernel.org (Postfix) with ESMTPS id C7122B81613; Mon, 16 May 2022 19:59:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39C80C385AA; Mon, 16 May 2022 19:59:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652731148; bh=wOIDV8q4QcRZSsv7ZtGikMXYBHgsMA3h+B5yP9HDWMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OZwehqRumQwM1rAwTJ3uBu20HlAFG3AAWw3KM60adhSLGvohZdbhJyHcMAnzvxsFQ WAIh0Gxm3ew9DOJVzG1CAK2TzPAD889QGavwSCsjZV6V6wF8/cYZqtOcZLy/axw+Xi hL/jRszV1i5m8KFa2JlNUVFKM0XqOk9tAddIJklI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hyeonggon Yoo <42.hyeyoo@gmail.com>, Marco Elver , Muchun Song , Alexander Potapenko , Dmitry Vyukov , Andrew Morton Subject: [PATCH 5.17 114/114] mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool Date: Mon, 16 May 2022 21:37:28 +0200 Message-Id: <20220516193628.745366269@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220516193625.489108457@linuxfoundation.org> References: <20220516193625.489108457@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hyeonggon Yoo <42.hyeyoo@gmail.com> commit 2839b0999c20c9f6bf353849c69370e121e2fa1a upstream. 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 Signed-off-by: Greg Kroah-Hartman --- mm/kfence/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -515,6 +515,7 @@ static bool __init kfence_init_pool(void { unsigned long addr = (unsigned long)__kfence_pool; struct page *pages; + char *p; int i; if (!__kfence_pool) @@ -598,6 +599,16 @@ err: * fails for the first page, and therefore expect addr==__kfence_pool in * most failure cases. */ + for (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;