Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 216.228.117.160 as permitted sender) receiver=protection.outlook.com;
 client-ip=216.228.117.160; helo=mail.nvidia.com; pr=C
From:   Haotien Hsu <haotienh@nvidia.com>
To:     JC Kuo <jckuo@nvidia.com>, Vinod Koul <vkoul@kernel.org>,
        "Kishon Vijay Abraham I" <kishon@kernel.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        <linux-phy@lists.infradead.org>, <linux-tegra@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     Wayne Chang <waynec@nvidia.com>, EJ Hsu <ejh@nvidia.com>,
        Haotien Hsu <haotienh@nvidia.com>
Subject: [PATCH] phy: tegra: xusb: Fix use-after-free issue
Date:   Thu, 4 May 2023 13:54:46 +0800
Message-ID: <20230504055446.2039372-1-haotienh@nvidia.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 May 2023 05:55:22.6810
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: fd61de34-4801-4e18-7a2d-08db4c642666
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT073.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB8474
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=no autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: EJ Hsu <ejh@nvidia.com>

For the dual-role port, it will assign the phy dev to usb-phy dev and
use the port dev driver as the dev driver of usb-phy.

When we try to destroy the port dev, it will destroy its dev driver
as well. But we did not remove the reference from usb-phy dev. This
might cause the use-after-free issue in KASAN.

Fixes: e8f7d2f409a1 ("phy: tegra: xusb: Add usb-phy support")
Cc: stable@vger.kernel.org

Signed-off-by: EJ Hsu <ejh@nvidia.com>
Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
---
 drivers/phy/tegra/xusb.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index 78045bd6c214..515298a9a433 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -563,13 +563,6 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port,
 
 static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
 {
-	if (!IS_ERR_OR_NULL(port->usb_role_sw)) {
-		of_platform_depopulate(&port->dev);
-		usb_role_switch_unregister(port->usb_role_sw);
-		cancel_work_sync(&port->usb_phy_work);
-		usb_remove_phy(&port->usb_phy);
-	}
-
 	if (port->ops->remove)
 		port->ops->remove(port);
 
@@ -832,6 +825,14 @@ void tegra_xusb_usb2_port_remove(struct tegra_xusb_port *port)
 {
 	struct tegra_xusb_usb2_port *usb2 = to_usb2_port(port);
 
+	if (!IS_ERR_OR_NULL(port->usb_role_sw)) {
+		of_platform_depopulate(&port->dev);
+		usb_role_switch_unregister(port->usb_role_sw);
+		cancel_work_sync(&port->usb_phy_work);
+		usb_remove_phy(&port->usb_phy);
+		port->usb_phy.dev->driver = NULL;
+	}
+
 	regulator_put(usb2->supply);
 }
 
-- 
2.25.1