From patchwork Thu Jan 7 14:31:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 359669 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 AD474C432C3 for ; Thu, 7 Jan 2021 14:38:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FEAD2311E for ; Thu, 7 Jan 2021 14:38:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729151AbhAGOcD (ORCPT ); Thu, 7 Jan 2021 09:32:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:45976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729100AbhAGObz (ORCPT ); Thu, 7 Jan 2021 09:31:55 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AB0D523384; Thu, 7 Jan 2021 14:30:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610029856; bh=j7wIWmPz4LCwK472zUBV70R6svjuVOVYEpgERvVCHsE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lAb/Kw+RQ04xmTwXKq70hFSsaIFE/NGZzPbq3AyCqHAWXb776t6D1+V5mEgtxzNwF 2yBpztAgJZgATwIu3GWczVIJFKl0Mi+8GctmMa7Qa+gVHk21mKyapV4naDUUfobVLU bTNXb/55utmvsxXeYTInSHdcHcvaRORY6nN3RmOg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kevin Vigor , Song Liu Subject: [PATCH 4.14 02/29] md/raid10: initialize r10_bio->read_slot before use. Date: Thu, 7 Jan 2021 15:31:17 +0100 Message-Id: <20210107143053.269861038@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210107143052.973437064@linuxfoundation.org> References: <20210107143052.973437064@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kevin Vigor commit 93decc563637c4288380912eac0eb42fb246cc04 upstream. In __make_request() a new r10bio is allocated and passed to raid10_read_request(). The read_slot member of the bio is not initialized, and the raid10_read_request() uses it to index an array. This leads to occasional panics. Fix by initializing the field to invalid value and checking for valid value in raid10_read_request(). Cc: stable@vger.kernel.org Signed-off-by: Kevin Vigor Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid10.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1120,7 +1120,7 @@ static void raid10_read_request(struct m struct md_rdev *err_rdev = NULL; gfp_t gfp = GFP_NOIO; - if (r10_bio->devs[slot].rdev) { + if (slot >= 0 && r10_bio->devs[slot].rdev) { /* * This is an error retry, but we cannot * safely dereference the rdev in the r10_bio, @@ -1513,6 +1513,7 @@ static void __make_request(struct mddev r10_bio->mddev = mddev; r10_bio->sector = bio->bi_iter.bi_sector; r10_bio->state = 0; + r10_bio->read_slot = -1; memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * conf->copies); if (bio_data_dir(bio) == READ)