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 3D800C7EE2C for ; Sat, 27 May 2023 01:17:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237395AbjE0BRx (ORCPT ); Fri, 26 May 2023 21:17:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229762AbjE0BRu (ORCPT ); Fri, 26 May 2023 21:17:50 -0400 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F22AED9; Fri, 26 May 2023 18:17:49 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4QSkRt22VNz4f3mHm; Sat, 27 May 2023 09:17:46 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP4 (Coremail) with SMTP id gCh0CgCH77I5WnFk4f4tKQ--.29659S3; Sat, 27 May 2023 09:17:47 +0800 (CST) Subject: Re: [PATCH v2 1/4] md/raid10: fix null-ptr-deref of mreplace in raid10_sync_request To: Song Liu , linan666@huaweicloud.com Cc: bingjingc@synology.com, allenpeng@synology.com, alexwu@synology.com, shli@fb.com, neilb@suse.de, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linan122@huawei.com, yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com, "yukuai (C)" References: <20230526074551.669792-1-linan666@huaweicloud.com> <20230526074551.669792-2-linan666@huaweicloud.com> From: Yu Kuai Message-ID: <5d836b41-2dff-e829-2e18-97ea4565b5bc@huaweicloud.com> Date: Sat, 27 May 2023 09:17:45 +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: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: gCh0CgCH77I5WnFk4f4tKQ--.29659S3 X-Coremail-Antispam: 1UD129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7v73 VFW2AGmfu7bjvjm3AaLaJ3UjIYCTnIWjp_UUUYv7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E 6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28Cjx kF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8I cVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87 Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE 6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72 CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4II rI8v6xkF7I0E8cxan2IY04v7Mxk0xIA0c2IEe2xFo4CEbIxvr21l42xK82IYc2Ij64vIr4 1l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK 67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI 8IcVAFwI0_JFI_Gr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAIw20E Y4v20xvaj40_Wr1j6rW3Jr1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbXdbUUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, 在 2023/05/27 5:38, Song Liu 写道: > On Fri, May 26, 2023 at 12:47 AM wrote: } > > To make sure I understand the issue correctly: > > The null-ptr-deref only happens when the Faulty bit was set after the > last check and before this check below, right? Yes, you're right. Thanks, Kuai > >> - if (mreplace && test_bit(Faulty, &mreplace->flags)) >> - mreplace = NULL; >> /* Unless we are doing a full sync, or a replacement >> * we only need to recover the block if it is set in >> * the bitmap > > Thanks, > Song >