From patchwork Tue Dec 21 08:10:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Peng X-Patchwork-Id: 12689243 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 71BA8C433F5 for ; Tue, 21 Dec 2021 08:11:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235414AbhLUIL1 (ORCPT ); Tue, 21 Dec 2021 03:11:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234701AbhLUIL1 (ORCPT ); Tue, 21 Dec 2021 03:11:27 -0500 Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E71DEC061574; Tue, 21 Dec 2021 00:11:26 -0800 (PST) Received: by mail-pg1-x531.google.com with SMTP id y9so11680020pgj.5; Tue, 21 Dec 2021 00:11:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=CNQ27S31DQKVMGNaa41vJ0MWzIDdPEbu6tohUmL45Xc=; b=pWK7rOOe6EgoIgreqR5MDZpNyU04GgACI0jFEnyQ7jExs/7udsljcJrTRwZEPfYbwd YkVlyFt10PL4riFiWcVbhu8LmpmmK2H0ZQVtO/z68Gyrsdhqd7Fnf5dneJzJ+LI6GzAL 9oCUXjCyX+2x+mrhIiSi1ZE/oyDDgMWJ4ihXNqpLPvF752E50HoZQDFsmvJl1jujPur7 +oR2aKa7zgfO1CFOFyJ55EYKbJqR4LZOWhVfPUx9BpozHtEnpoQ2fUA0U1BXMdos+56s Mi+wCnO9sOOaWnXXwVOuDesraAB8rkTU6lpx+r9R7Q3I2BDYwJnouyEcaOvJaxArG7KY i18Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=CNQ27S31DQKVMGNaa41vJ0MWzIDdPEbu6tohUmL45Xc=; b=7zSa4bwpPwUv4ZB8LnXvLK2cfZzal3TLTcukTKbefafGC5so4o2Pg4Z1viYjCAuyhU DkgD0KQGi8dFyi/WbTRiE1bx5Rq8DQOeQRg4hsuuqXZg3zl+Ao8OI56GFvLBHZqjPyej hi6N2RYM1M46tv6h0LYCK+h0CLRT/cQqQQsnLoQsAizC9tSLdqXvG8bmo11OaLjFi2IY KoKj7unNfX8VK2upB32/jmCDpkz6Qm9FZgx3lgHNdgGKSlChNacI34HMprAzo4X8120y Jw/0/bJHD+Nzq+nsL2R0x3sObTW6Wu7gGU+dRsAsyJPJnT9ffw9ZsGp+NwvKAIZbUVil 8fgA== X-Gm-Message-State: AOAM530WXUtvlBz8lLwSPuL8LbRHvwon0NkBO/QU2+5bnwn3k825ncRT K8B1InUPPS+C2NWhfHtdWjgoEnw/pqM= X-Google-Smtp-Source: ABdhPJzivj4IPkq9WcmMOBNQPCbJy7iEXusOZPE0zZnBwVmWYQio52v+igjnlqR4d8Jn8/gjmKRBYA== X-Received: by 2002:a62:8042:0:b0:4a8:15eb:db10 with SMTP id j63-20020a628042000000b004a815ebdb10mr2128313pfd.28.1640074286391; Tue, 21 Dec 2021 00:11:26 -0800 (PST) Received: from FLYINGPENG-MB0.tencent.com ([103.7.29.30]) by smtp.gmail.com with ESMTPSA id t8sm21024635pfj.26.2021.12.21.00.11.24 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Dec 2021 00:11:26 -0800 (PST) From: Peng Hao X-Google-Original-From: Peng Hao To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] block/elevator: handle possible null pointer Date: Tue, 21 Dec 2021 16:10:42 +0800 Message-Id: <20211221081042.78799-1-flyingpeng@tencent.com> X-Mailer: git-send-email 2.30.1 (Apple Git-130) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There is a check for q->tag_set in the front of elevator_get_default, and there should be a check here too. Signed-off-by: Peng Hao --- block/elevator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/elevator.c b/block/elevator.c index 1f39f6e8ebb9..b7d0bead680c 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -636,7 +636,7 @@ static struct elevator_type *elevator_get_default(struct request_queue *q) if (q->tag_set && q->tag_set->flags & BLK_MQ_F_NO_SCHED_BY_DEFAULT) return NULL; - if (q->nr_hw_queues != 1 && + if (q->nr_hw_queues != 1 && q->tag_set && !blk_mq_is_shared_tags(q->tag_set->flags)) return NULL;