[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [PATCH 3/6] VT-d: don't leak domid mapping on error path


  • To: Jan Beulich <jbeulich@xxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
  • Date: Mon, 15 Nov 2021 05:21:25 +0000
  • Accept-language: en-US
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=FgcTmuzke/9024I1ZH8oHXqHgnuL2fsWV6++ybbcNOk=; b=DkQj4YDZK5B0oVsemPvipxF8xTd9eDeijR88atorcYUiPmquiTYcB7hmFOj5WpvOVN+OcR0EbVp52FqFutryVnDTUdEgACIWmmA8eTqme+tJS/Mf+idW6npaVV8Xl4zfWVsR9I94EMAWMpJhmhkErmD/LTAiNLTED4hbU4x8YnEPr15IaBykGHxgusVZFIqtCilXvBnBqE+WZ6CcDFuSR4Hq/tYOS+rvUBEBHVzaMv9qNJNnSdg+m9XofCGW6Yc7DuaC4GxwTz3x96mJYEOaM6CcP4kPwCXjHFTr7O7kJCkpodSv2985zpsMOrtXDF4MrwBePFcLC6A9BGUngaj2hw==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=np85Ryb9crwgF6SJH5I8xMBVJO6dECZ1K2WKJN5Yv2pn4aFxDKTdPA9ISuaZ/d01jzQfMruX5/4iG/9C8uBG1m15tqtBjHOeFRfER7s6BgK9dVyQGMJpa+sQXHqn37kD6hy+wO1et93mXP/2IQdQZA8sR4rdIL5Q1LLFSpR/1iO9RMVBSP3BPtX0gatp9N5Z8+JwAzRVZ7M8ivwWi2GzGRqIPC5XuP2Qr6fdFw/mi40a0IYySHoUcwl4g+DUwgpqjzwDmpuL+s3ES1m0AoaL4IHWX01w50Pk+BzO+ZEtKaImvqasHVkluAGhNR1CV6sw6R52ti8j1Zqv3qlsmsSGUg==
  • Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com;
  • Delivery-date: Mon, 15 Nov 2021 05:21:42 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
  • Thread-index: AQHX16qEmEl05LhWzEygD9JPD9Hti6wEEdqw
  • Thread-topic: [PATCH 3/6] VT-d: don't leak domid mapping on error path

> From: Jan Beulich <jbeulich@xxxxxxxx>
> Sent: Friday, November 12, 2021 5:49 PM
> 
> While domain_context_mapping() invokes domain_context_unmap() in a
> sub-
> case of handling DEV_TYPE_PCI when encountering an error, thus avoiding
> a leak, individual calls to domain_context_mapping_one() aren't
> similarly covered. Such a leak might persist until domain destruction.
> Leverage that these cases can be recognized by pdev being non-NULL.
> 
> Fixes: dec403cc668f ("VT-d: fix iommu_domid for PCI/PCIx devices
> assignment")
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>

> ---
> The Fixes: tag isn't strictly correct, as error handling had more severe
> shortcomings at the time. But I wouldn't want to blame a commit
> improving error handling to have introduced the leak.
> 
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -1518,7 +1518,12 @@ int domain_context_mapping_one(
>          rc = me_wifi_quirk(domain, bus, devfn, MAP_ME_PHANTOM_FUNC);
> 
>      if ( rc )
> -        domain_context_unmap_one(domain, iommu, bus, devfn);
> +    {
> +        ret = domain_context_unmap_one(domain, iommu, bus, devfn);
> +
> +        if ( !ret && pdev && pdev->devfn == devfn )
> +            check_cleanup_domid_map(domain, pdev, iommu);
> +    }
> 
>      return rc;
>  }


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.