From nobody Sat Oct 4 00:21:30 2025 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (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 6A6AF2F5483; Fri, 22 Aug 2025 10:39:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755859152; cv=none; b=bXyNZmB6FE2KGlsffi8OCljXCyTLV5JciOOHV43mNJ7axP5COP6/ShzU0hmADuQJssIB2PmZiHms3dUPEVCx3MJ2JxXWlh0sKURlfHBEBf8VQ3NJtg3k1ybhXq3UpSobxGlVF7FCW4YIGucJsCVi4SOHy8/84Kqa5x4V/uW5dWE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755859152; c=relaxed/simple; bh=5OW9O5RwyETlN8vXUqm94SQB4JN1rvICtu20k9gCrQM=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=KcIQZnYGOvXwEcClnZmLPHy6rjItgIhXFv8gaI7nF5puC+gIDn2yw83M8eV/KsDxHQ2XE9BPxb7KuidS2UxNQZFObkOhhsWvfMqTHM8CEGDSjMQ7NRzcnlIt00VKbMALhjEZbZYtjsFfONTFZcmAxlGs+jiLZDeg9P9FfSX1DFA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4c7c6j3dN8z1R8yS; Fri, 22 Aug 2025 18:36:13 +0800 (CST) Received: from dggemv706-chm.china.huawei.com (unknown [10.3.19.33]) by mail.maildlp.com (Postfix) with ESMTPS id 816F6140258; Fri, 22 Aug 2025 18:39:07 +0800 (CST) Received: from kwepemq200001.china.huawei.com (7.202.195.16) by dggemv706-chm.china.huawei.com (10.3.19.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 22 Aug 2025 18:39:07 +0800 Received: from localhost.huawei.com (10.90.31.46) by kwepemq200001.china.huawei.com (7.202.195.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 22 Aug 2025 18:39:06 +0800 From: Chenghai Huang To: , , CC: , , , , , , , Subject: [PATCH 4/4] uacce: ensure safe queue release with state management Date: Fri, 22 Aug 2025 18:39:04 +0800 Message-ID: <20250822103904.3776304-5-huangchenghai2@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20250822103904.3776304-1-huangchenghai2@huawei.com> References: <20250822103904.3776304-1-huangchenghai2@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemq200001.china.huawei.com (7.202.195.16) Content-Type: text/plain; charset="utf-8" Directly calling `put_queue` carries risks since it cannot guarantee that resources of `uacce_queue` have been fully released beforehand. So adding a `stop_queue` operation for the UACCE_CMD_PUT_Q command and leaving the `put_queue` operation to the final resource release ensures safety. Queue states are defined as follows: - UACCE_Q_ZOMBIE: Initial state - UACCE_Q_INIT: After opening `uacce` - UACCE_Q_STARTED: After `start` is issued via `ioctl` When executing `poweroff -f` in virt while accelerator are still working, `uacce_fops_release` and `uacce_remove` may execute concurrently. This can cause `uacce_put_queue` within `uacce_fops_release` to access a NULL `ops` pointer. Therefore, add state checks to prevent accessing freed pointers. Fixes: 015d239ac014 ("uacce: add uacce driver") Signed-off-by: Chenghai Huang Signed-off-by: Yang Shen --- drivers/misc/uacce/uacce.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c index 531a24145ba4..8a78edb545a1 100644 --- a/drivers/misc/uacce/uacce.c +++ b/drivers/misc/uacce/uacce.c @@ -40,20 +40,34 @@ static int uacce_start_queue(struct uacce_queue *q) return 0; } =20 -static int uacce_put_queue(struct uacce_queue *q) +static int uacce_stop_queue(struct uacce_queue *q) { struct uacce_device *uacce =3D q->uacce; =20 - if ((q->state =3D=3D UACCE_Q_STARTED) && uacce->ops->stop_queue) + if (q->state !=3D UACCE_Q_STARTED) + return 0; + + if (uacce->ops->stop_queue) uacce->ops->stop_queue(q); =20 - if ((q->state =3D=3D UACCE_Q_INIT || q->state =3D=3D UACCE_Q_STARTED) && - uacce->ops->put_queue) + q->state =3D UACCE_Q_INIT; + + return 0; +} + +static void uacce_put_queue(struct uacce_queue *q) +{ + struct uacce_device *uacce =3D q->uacce; + + uacce_stop_queue(q); + + if (q->state !=3D UACCE_Q_INIT) + return; + + if (uacce->ops->put_queue) uacce->ops->put_queue(q); =20 q->state =3D UACCE_Q_ZOMBIE; - - return 0; } =20 static long uacce_fops_unl_ioctl(struct file *filep, @@ -80,7 +94,7 @@ static long uacce_fops_unl_ioctl(struct file *filep, ret =3D uacce_start_queue(q); break; case UACCE_CMD_PUT_Q: - ret =3D uacce_put_queue(q); + ret =3D uacce_stop_queue(q); break; default: if (uacce->ops->ioctl) --=20 2.33.0