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 6F2FFC77B6C for ; Mon, 3 Apr 2023 14:16:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232955AbjDCOQf (ORCPT ); Mon, 3 Apr 2023 10:16:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232844AbjDCOQb (ORCPT ); Mon, 3 Apr 2023 10:16:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97CA027839 for ; Mon, 3 Apr 2023 07:16:30 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 2C3AE61CCB for ; Mon, 3 Apr 2023 14:16:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F0D4C433EF; Mon, 3 Apr 2023 14:16:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680531389; bh=K7U3p9dxigxgiCWi0s0u9AxjdxF3i2JymFR1MdnCrVc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wLgX6bksptNFRNQ9xUUa1bUin9OX6tXIsA4kz68khKfcqSeX9DzpgRO9r020WWMxy mvHS3IDHIdSpngtrEcYy1RqErOrcSAQSjHRIwO8zerTmVSRjbiBZllWltMEriiCnsZ tIGC+SpV9dU5x9kKgZeAR/K4blEImvTiEtKsJ/WA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiasheng Jiang , Mike Snitzer Subject: [PATCH 4.19 45/84] dm stats: check for and propagate alloc_percpu failure Date: Mon, 3 Apr 2023 16:08:46 +0200 Message-Id: <20230403140354.938390879@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140353.406927418@linuxfoundation.org> References: <20230403140353.406927418@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jiasheng Jiang commit d3aa3e060c4a80827eb801fc448debc9daa7c46b upstream. Check alloc_precpu()'s return value and return an error from dm_stats_init() if it fails. Update alloc_dev() to fail if dm_stats_init() does. Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup() even if dm-stats isn't being actively used. Fixes: fd2ed4d25270 ("dm: add statistics support") Cc: stable@vger.kernel.org Signed-off-by: Jiasheng Jiang Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-stats.c | 7 ++++++- drivers/md/dm-stats.h | 2 +- drivers/md/dm.c | 4 +++- 3 files changed, 10 insertions(+), 3 deletions(-) --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -188,7 +188,7 @@ static int dm_stat_in_flight(struct dm_s atomic_read(&shared->in_flight[WRITE]); } -void dm_stats_init(struct dm_stats *stats) +int dm_stats_init(struct dm_stats *stats) { int cpu; struct dm_stats_last_position *last; @@ -196,11 +196,16 @@ void dm_stats_init(struct dm_stats *stat mutex_init(&stats->mutex); INIT_LIST_HEAD(&stats->list); stats->last = alloc_percpu(struct dm_stats_last_position); + if (!stats->last) + return -ENOMEM; + for_each_possible_cpu(cpu) { last = per_cpu_ptr(stats->last, cpu); last->last_sector = (sector_t)ULLONG_MAX; last->last_rw = UINT_MAX; } + + return 0; } void dm_stats_cleanup(struct dm_stats *stats) --- a/drivers/md/dm-stats.h +++ b/drivers/md/dm-stats.h @@ -22,7 +22,7 @@ struct dm_stats_aux { unsigned long long duration_ns; }; -void dm_stats_init(struct dm_stats *st); +int dm_stats_init(struct dm_stats *st); void dm_stats_cleanup(struct dm_stats *st); struct mapped_device; --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2021,7 +2021,9 @@ static struct mapped_device *alloc_dev(i bio_set_dev(&md->flush_bio, md->bdev); md->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC; - dm_stats_init(&md->stats); + r = dm_stats_init(&md->stats); + if (r < 0) + goto bad; /* Populate the mapping, nobody knows we exist yet */ spin_lock(&_minor_lock);