From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DEC8D1391; Thu, 15 Jan 2026 05:33:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768455186; cv=none; b=opAERmdExn7UFgCRHoBJqcLNCXauO7+kTbwXedPjXJWM8JZpAmCmyNhBbdDbE5Kr99+KdUvoM4hH3aUnoPHiJhj3OAdNsfNggs9KyN51NGDp23k3YvAEzekdKO1cKcMBJHMknHul8vZ9YQiB1YQfhs44Nlo84Cj5qvtvgCCuJQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768455186; c=relaxed/simple; bh=c5y1K8Iw/JBlnaServwJ53zjp00ciMj2On1YPP2ODNc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BdTwXBxLa9XiONmk/uGuvL+hQ6PMbkQ3IilYX2LME9xeAeMkwuagtK6gTxjFtry1TV0vAlIh9q/vidZNsIfNnAewFRCqk0k4JiBo0qmuQnN244QXvy/0MTCy7FLv62wov6lgbSRR4BySJSWdW1Kc9T2SY/QgH3zqcH/RdjOzwdU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.170]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4dsBSS2005zKHMQK; Thu, 15 Jan 2026 13:32:08 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 641784056B; Thu, 15 Jan 2026 13:33:01 +0800 (CST) Received: from [10.174.178.72] (unknown [10.174.178.72]) by APP4 (Coremail) with SMTP id gCh0CgAXxfULfGhpImBxDw--.58413S3; Thu, 15 Jan 2026 13:33:01 +0800 (CST) Message-ID: <2685a1b2-9c68-4b14-87bc-96c19a0a2e48@huaweicloud.com> Date: Thu, 15 Jan 2026 13:32:56 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/3] blk-cgroup: fix race between policy activation and blkg destruction To: =?UTF-8?Q?Michal_Koutn=C3=BD?= Cc: tj@kernel.org, josef@toxicpanda.com, axboe@kernel.dk, yukuai3@huawei.com, hch@infradead.org, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, houtao1@huawei.com, Zheng Qixing References: <20260113061035.1902522-1-zhengqixing@huaweicloud.com> <20260113061035.1902522-2-zhengqixing@huaweicloud.com> From: Zheng Qixing In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:gCh0CgAXxfULfGhpImBxDw--.58413S3 X-Coremail-Antispam: 1UD129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7v73 VFW2AGmfu7bjvjm3AaLaJ3UjIYCTnIWjp_UUUYV7kC6x804xWl14x267AKxVW8JVW5JwAF c2x0x2IEx4CE42xK8VAvwI8IcIk0rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII 0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xv wVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4 x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG 64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r 1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwACI402YVCY1x02628vn2kI c2xKxwCF04k20xvY0x0EwIxGrwCF54CYxVCY1x0262kKe7AKxVWUtVW8ZwCFx2IqxVCFs4 IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1r MI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJV WUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j 6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYx BIdaVFxhVjvjDU0xZFpf9x07UWE__UUUUU= X-CM-SenderInfo: x2kh0wptl0x03j6k3tpzhluzxrxghudrp/ Resend... blkcg_activate_policy()                blkg_free_workfn() -------------------                    ------------------ spin_lock(&q->queue_lock) ... if (!pd) {     spin_unlock(&q->queue_lock)     ...     goto enomem     } enomem:     spin_lock(&q->queue_lock)     if (pd) { ->pd_free_fn()  // pd freed        pd->online // uaf        ...     } spin_lock(&q->queue_lock) list_del_init(&blkg->q_node) spin_unlock(&q->queue_lock)