Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: [PATCH 01/12] swiotlb-xen: avoid double free
From:   Jan Beulich <jbeulich@suse.com>
To:     Juergen Gross <jgross@suse.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc:     Stefano Stabellini <sstabellini@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
References: <588b3e6d-2682-160c-468e-44ca4867a570@suse.com>
Message-ID: <ce9c2adb-8a52-6293-982a-0d6ece943ac6@suse.com>
Date:   Tue, 7 Sep 2021 14:04:25 +0200
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.13.0
In-Reply-To: <588b3e6d-2682-160c-468e-44ca4867a570@suse.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-MessageSentRepresentingType: 1
Received: from [10.156.60.236] (37.24.206.209) by AM0PR04CA0096.eurprd04.prod.outlook.com (2603:10a6:208:be::37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4500.14 via Frontend Transport; Tue, 7 Sep 2021 12:04:26 +0000
X-MS-PublicTrafficType: Email
X-MS-Office365-Filtering-Correlation-Id: 921de9e7-79f6-4e70-1d37-08d971f7a410
X-MS-TrafficTypeDiagnostic: VI1PR04MB3120:
X-LD-Processed: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba,ExtFwd
X-MS-Exchange-Transport-Forked: True
X-Microsoft-Antispam-PRVS: <VI1PR04MB312004B434F20DB2E967D513B3D39@VI1PR04MB3120.eurprd04.prod.outlook.com>
X-MS-Oob-TLC-OOBClassifiers: OLM:4714;
X-MS-Exchange-SenderADCheck: 1
X-MS-Exchange-AntiSpam-Relay: 0
X-Microsoft-Antispam: BCL:0;
X-Microsoft-Antispam-Message-Info: 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
X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR04MB5600.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(39860400002)(136003)(396003)(376002)(366004)(346002)(6486002)(956004)(38100700002)(2616005)(86362001)(316002)(16576012)(83380400001)(26005)(186003)(36756003)(4326008)(2906002)(66946007)(66476007)(478600001)(66556008)(5660300002)(8676002)(31686004)(110136005)(54906003)(8936002)(4744005)(31696002)(45980500001)(43740500002);DIR:OUT;SFP:1101;
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?d3FudDlzTVc5RUZZeWhhMWJyUEx6Rm5IaXAzWUZ0MmgrMUcrYjJNK1VMYUJS?=
 =?utf-8?B?U3paOGsxT2llZDNNMVBaakdUMEtNTzBzNmJzMTJKNlZmUm5oeXZhS05hWEhk?=
 =?utf-8?B?VnFZdGNHK1o3cmtIR3pIRzRFQVdjUzc2d0VkdWtIQlpLbDFWOE1WTENQMnRi?=
 =?utf-8?B?b2pUR3pQc1p1MUpGZ2lZRklKRjliRWdEYkZCZGhuQmpYdVc3SysvQ253aG9P?=
 =?utf-8?B?d1lHNDdTMXIxVGdOZXIxWUE2STluVjRPTVhoYnQxcnNtUWYzU0N5OWhqTE1a?=
 =?utf-8?B?VnNlMWNnL1hhT3lJLy94TW9jbzVnY1NnaVlpd1ZCbXJrV3k3ajIyTDRiOVZh?=
 =?utf-8?B?Q2E0QzJGL3dqVThtWE1UV2pYVTRQUmpqRGZsdkxMa1BDSDR6ZTA1RW1NWjBP?=
 =?utf-8?B?NWlaMzEvUjNidEpjekpMUmdQMFZkOVZWRnArSTlLNE1MSFdKWXkxekdIcWla?=
 =?utf-8?B?NElCck5iS0hudjhpcGoyL2FQS3hlVGZhQWEvWnI4L3lVOG5hRU12VVZBeHNN?=
 =?utf-8?B?RmhoVmlkZjViSUVyaUw1OC8rbGtCTGQzZHJxb3h0NDFTdzlRbCt6K1N5Ylhn?=
 =?utf-8?B?N1pFNE91ZHJZTGZnS1NqYkRvVWh0Ukx1WEg2M1Z4cC9FT0cycVJiNDFldDJF?=
 =?utf-8?B?dWJXY0VqVWxQbzF6STZHNHdvZ1U0NTB1dVZiT01sWHpBeXNYbnFpZE9qTXpZ?=
 =?utf-8?B?Tkk5OTZrVzhCY0JlM2xFVG4zM25xRjVnSncySXIzYjBtdGV6TUhxWFQweVJD?=
 =?utf-8?B?V0hrMEsxWmN2L3JPTjRIU3VIbldoZTRFT3ZnbW1PckZqZUcxbTBzbG15dWc0?=
 =?utf-8?B?cUx2T0h3WWQwdDFreUVGMzFMTE1wM3NtQjZ5ZkFuM2NvWWhXN2Q1VDFNV3ow?=
 =?utf-8?B?ZUp6R3BxOVJnUGVZY3JETnRya3d4WGZXNzRNK0I0VHpEQ1BLWWFiRE5KTkpY?=
 =?utf-8?B?VzUyZXV0MlBoY2M1VHlTaW8rRWxBbHZmSzhkTHloRFlSS05TQS8yMWxWY3J4?=
 =?utf-8?B?Y3FaZ1Y3WVZjbWJaOHBsdnlSaFRMTUtIeFd6T1g1WlVDOXRqWURoWGRZc2tt?=
 =?utf-8?B?a2hjOWtDTDBLaG5LaW1sUWdONnRvWkdSd1R2NVRhalhGMU9PM3ZkRTJoU1Vi?=
 =?utf-8?B?QWc3OUF6c04wZ1BwQ2EzYWgwRC9HZVY3cmhlOHV3YVJiYnZkcUY5VHhhV2sr?=
 =?utf-8?B?MFV0L213TXZncU52KzZJeTVncjZHQUtqbWFPdFN6TnVEVTRvQUdBQmh1MFo0?=
 =?utf-8?B?WmpQdEdOYmM1dE4xMy9OTW5FbVYwTU4yRllvakJvR1B4b29La2dya2FrSUJC?=
 =?utf-8?B?cjcyZlpVZnB1bVVaVzQ0Nm1rL3QrS0FxbFp6MEpWQ2pOWlA1Q2hkeHNoTVZu?=
 =?utf-8?B?QzJjQlNJZGZMMU41UUREdTZNalRlRnJycU1IdFVHZFl0MzR0d2ZReEdTTGRa?=
 =?utf-8?B?L0xpaUJjdDlhQTk3bkE2MkkwMUF2Zm9DMXR2eFZsVFNGVHN5K3dPdTdaQko3?=
 =?utf-8?B?WDFzTjQ5Z0JOMEZtc25KQnRzZ3BOZUdjTlp1WkZjM1FQSnpoSFhqUGUyVkRs?=
 =?utf-8?B?YVhObzRQMDV3eTZsRXdsTHE0R255SWtVdVRKbTVNYjQxa2VheTIybXpTM3Y3?=
 =?utf-8?B?VVNnOWNsRDY5OENWVU8yckxqVVBrY0E0ZUVQUXNDSzdCeU5sNVFwV1JrbjJH?=
 =?utf-8?B?NWE2TldNR21oVm8yV0R4SHdubTRqZ3RRVEtuR3FOelJBbnlHRkh5MFdFTmpW?=
 =?utf-8?Q?WAG8SzkZU1bnjyZ9mtOD9I9rNAZYcDqmM+yfsrP?=
X-OriginatorOrg: suse.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 921de9e7-79f6-4e70-1d37-08d971f7a410
X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5600.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Sep 2021 12:04:27.4045
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: fxmyLLc2/qK2sEN83kbQC4/qg3WM3+6UGQu1CSP/kkah2+uudkIas1308gmuLjq4QwRWerOTYZ0iL0+NKi/ObQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB3120
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Of the two paths leading to the "error" label in xen_swiotlb_init() one
didn't allocate anything, while the other did already free what was
allocated.

Fixes: b82776005369 ("xen/swiotlb: Use the swiotlb_late_init_with_tbl to init Xen-SWIOTLB late when PV PCI is used")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org

--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -216,7 +216,6 @@ error:
 		goto retry;
 	}
 	pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc);
-	free_pages((unsigned long)start, order);
 	return rc;
 }