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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB562ECDE44 for ; Wed, 31 Oct 2018 23:08:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B474F20838 for ; Wed, 31 Oct 2018 23:08:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="lVtPh7hH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B474F20838 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728273AbeKAIIS (ORCPT ); Thu, 1 Nov 2018 04:08:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:56986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729541AbeKAIIR (ORCPT ); Thu, 1 Nov 2018 04:08:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7BE682064C; Wed, 31 Oct 2018 23:08:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541027286; bh=/tR8YccqR6H7OVYXj8f2wMIYOSxWoY2tVx094jQezgU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lVtPh7hH+MSDY4qJ/R6aFyhYFBHJYoJCWAK/aDCEoPwcrkevbpa9yabDD0FZ2hG4p MPQCEp1K2FhdcC8BWVTDh21eu9qENDRuxJ74Q4jGQpHVQm7S9onQV9D4Jxxhkybia+ 9h7kEjRYIsy1riUdZ8vfQVTY67vMgkbf0iSe1SPY= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Matias=20Bj=C3=B8rling?= , Jens Axboe , Sasha Levin Subject: [PATCH AUTOSEL 4.18 012/126] lightnvm: pblk: fix race on sysfs line state Date: Wed, 31 Oct 2018 19:06:00 -0400 Message-Id: <20181031230754.29029-12-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181031230754.29029-1-sashal@kernel.org> References: <20181031230754.29029-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Javier González [ Upstream commit 44cdbdc657b23f75736eca3e88b781f009104363 ] pblk exposes a sysfs interface that represents its internal state. Part of this state is the map bitmap for the current open line, which should be protected by the line lock to avoid a race when freeing the line metadata. Currently, it is not. This patch makes sure that the line state is consistent and NULL bitmap pointers are not dereferenced. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/lightnvm/pblk-core.c | 5 +++-- drivers/lightnvm/pblk-sysfs.c | 8 +++++++- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c index ed9cc977c8b3..f6427e805150 100644 --- a/drivers/lightnvm/pblk-core.c +++ b/drivers/lightnvm/pblk-core.c @@ -1538,13 +1538,14 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk) struct pblk_line *cur, *new = NULL; unsigned int left_seblks; - cur = l_mg->data_line; new = l_mg->data_next; if (!new) goto out; - l_mg->data_line = new; spin_lock(&l_mg->free_lock); + cur = l_mg->data_line; + l_mg->data_line = new; + pblk_line_setup_metadata(new, l_mg, &pblk->lm); spin_unlock(&l_mg->free_lock); diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c index 88a0a7c407aa..432f7d94d369 100644 --- a/drivers/lightnvm/pblk-sysfs.c +++ b/drivers/lightnvm/pblk-sysfs.c @@ -262,8 +262,14 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page) sec_in_line = l_mg->data_line->sec_in_line; meta_weight = bitmap_weight(&l_mg->meta_bitmap, PBLK_DATA_LINES); - map_weight = bitmap_weight(l_mg->data_line->map_bitmap, + + spin_lock(&l_mg->data_line->lock); + if (l_mg->data_line->map_bitmap) + map_weight = bitmap_weight(l_mg->data_line->map_bitmap, lm->sec_per_line); + else + map_weight = 0; + spin_unlock(&l_mg->data_line->lock); } spin_unlock(&l_mg->free_lock); -- 2.17.1