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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72A6DC4332F for ; Tue, 8 Nov 2022 13:15:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234369AbiKHNPQ (ORCPT ); Tue, 8 Nov 2022 08:15:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233751AbiKHNPO (ORCPT ); Tue, 8 Nov 2022 08:15:14 -0500 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6103B27B20; Tue, 8 Nov 2022 05:15:13 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4N67qv3Tfsz4f3mJP; Tue, 8 Nov 2022 21:15:07 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP1 (Coremail) with SMTP id cCh0CgAn0a9cVmpjc06yAA--.42643S3; Tue, 08 Nov 2022 21:15:10 +0800 (CST) Subject: Re: [PATCH] block, bfq: fix null pointer dereference in bfq_bio_bfqg() To: Jan Kara , Yu Kuai Cc: tj@kernel.org, josef@toxicpanda.com, axboe@kernel.dk, paolo.valente@linaro.org, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, "yukuai (C)" References: <20221108103434.2853269-1-yukuai1@huaweicloud.com> <20221108124841.et6cddvczncp2cz7@quack3> From: Yu Kuai Message-ID: <6cd64e77-e14d-ff9c-d97f-055165a7b214@huaweicloud.com> Date: Tue, 8 Nov 2022 21:15:08 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20221108124841.et6cddvczncp2cz7@quack3> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: cCh0CgAn0a9cVmpjc06yAA--.42643S3 X-Coremail-Antispam: 1UD129KBjvdXoW7JFykGr45WFy5AFWDXF43ZFb_yoW3Crb_Gw 10yw10yFyDA3ySyr1qyr1aqa9YyrZ2qwna9r1YkFZ3Z3WkJan7A3srGw48JrZxCry8Cr1a vrn8Xwn3GFn5ZjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb3xFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr0_ Cr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s 1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0 cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8Jw ACjcxG0xvEwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkI wI1lc7I2V7IY0VAS07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbV WUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF 67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42 IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1l IxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvf C2KfnxnUUI43ZEXa7VUbXdbUUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! ÔÚ 2022/11/08 20:48, Jan Kara дµÀ: > > Hum, that is indeed contrieved ;). Your fixup makes sense so feel free to > add: > > Reviewed-by: Jan Kara Thanks for the review, our test do many unusual operations together... Thanks, Kuai > > Honza > >> >> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c >> index 144bca006463..7d624a3a3f0f 100644 >> --- a/block/bfq-cgroup.c >> +++ b/block/bfq-cgroup.c >> @@ -610,6 +610,10 @@ struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio) >> struct bfq_group *bfqg; >> >> while (blkg) { >> + if (!blkg->online) { >> + blkg = blkg->parent; >> + continue; >> + } >> bfqg = blkg_to_bfqg(blkg); >> if (bfqg->online) { >> bio_associate_blkg_from_css(bio, &blkg->blkcg->css); >> -- >> 2.31.1 >>