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=-16.8 required=3.0 tests=BAYES_00, 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 6AF51C47092 for ; Wed, 2 Jun 2021 10:07:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41D936121D for ; Wed, 2 Jun 2021 10:07:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230193AbhFBKIr (ORCPT ); Wed, 2 Jun 2021 06:08:47 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50837 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230178AbhFBKIr (ORCPT ); Wed, 2 Jun 2021 06:08:47 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1loNm7-0006tS-AK; Wed, 02 Jun 2021 10:06:59 +0000 From: Colin King To: Jens Axboe , Damien Le Moal , Christoph Hellwig , Ulf Hansson , linux-block@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] null_blk: Fix null pointer dereference on nullb->disk on blk_cleanup_disk call Date: Wed, 2 Jun 2021 11:06:59 +0100 Message-Id: <20210602100659.11058-1-colin.king@canonical.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Colin Ian King The error handling on a nullb->disk allocation currently jumps to out_cleanup_disk that calls blk_cleanup_disk with a null pointer causing a null pointer dereference issue. Fix this by jumping to out_cleanup_tags instead. Addresses-Coverity: ("Dereference after null check") Fixes: 132226b301b5 ("null_blk: convert to blk_alloc_disk/blk_cleanup_disk") Signed-off-by: Colin Ian King --- drivers/block/null_blk/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index d8e098f1e5b5..83d803cb57c8 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -1856,7 +1856,7 @@ static int null_add_dev(struct nullb_device *dev) goto out_cleanup_tags; nullb->disk = alloc_disk_node(1, nullb->dev->home_node); if (!nullb->disk) - goto out_cleanup_disk; + goto out_cleanup_tags; nullb->disk->queue = nullb->q; } else if (dev->queue_mode == NULL_Q_BIO) { rv = -ENOMEM; -- 2.31.1