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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 v2] phy: tegra: xusb: Fix use-after-free issue
Date:   Mon, 8 May 2023 18:03:20 +0800
Message-ID: <20230508100320.345673-1-haotienh@nvidia.com>
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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>
---
V1 -> V2: Remove extra movements to clarify the change
---
 drivers/phy/tegra/xusb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index 78045bd6c214..26b66a668f3b 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -568,6 +568,7 @@ static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
 		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;
 	}
 
 	if (port->ops->remove)
-- 
2.25.1