From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 344235683 for ; Mon, 3 Apr 2023 14:12:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC204C433D2; Mon, 3 Apr 2023 14:12:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680531153; bh=5Aj1WDgmJuiy/Os2qodk5equlpRlTUvzFYYPHGKMqwE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fj2RMdmABe6OC0T4ofteTx5E//KVgDFz2KHPPXAcWCq8C7pF+IB+XGO7wH+JAOA5n N0n01MsXcJYK73WhD8t5akcyLVJ86jRusDl8ztUcyCYbyrc1qnDLKOk97bTkMhRx9I TdEzXIHxK2qPzR9ApVA9kV0/3BWHDE9JTuo8pI+U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiasheng Jiang , Mike Snitzer Subject: [PATCH 4.14 38/66] dm stats: check for and propagate alloc_percpu failure Date: Mon, 3 Apr 2023 16:08:46 +0200 Message-Id: <20230403140353.217296171@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140351.636471867@linuxfoundation.org> References: <20230403140351.636471867@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -1799,7 +1799,9 @@ 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);