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From:   Evgeny Novikov <novikov@ispras.ru>
To:     Felipe Balbi <balbi@kernel.org>
Cc:     Evgeny Novikov <novikov@ispras.ru>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Corentin Labbe <clabbe@baylibre.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        ldv-project@linuxtesting.org
Subject: [PATCH] usb: gadget: goku_udc: fix potential crashes in probe
Date:   Fri,  2 Oct 2020 18:01:55 +0300
Message-Id: <20201002150155.7560-1-novikov@ispras.ru>
Precedence: bulk

goku_probe() goes to error label "err" and invokes goku_remove()
in case of failures of pci_enable_device(), pci_resource_start()
and ioremap(). goku_remove() gets a device from
pci_get_drvdata(pdev) and works with it without any checks, in
particular it dereferences a corresponding pointer. But
goku_probe() did not set this device yet. So, one can expect
various crashes. The patch moves setting the device just after
allocation of memory for it.

Found by Linux Driver Verification project (linuxtesting.org).

Reported-by: Pavel Andrianov <andrianov@ispras.ru>
Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
---
 drivers/usb/gadget/udc/goku_udc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/goku_udc.c b/drivers/usb/gadget/udc/goku_udc.c
index 25c1d6ab5adb..3e1267d38774 100644
--- a/drivers/usb/gadget/udc/goku_udc.c
+++ b/drivers/usb/gadget/udc/goku_udc.c
@@ -1760,6 +1760,7 @@ static int goku_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto err;
 	}
 
+	pci_set_drvdata(pdev, dev);
 	spin_lock_init(&dev->lock);
 	dev->pdev = pdev;
 	dev->gadget.ops = &goku_ops;
@@ -1793,7 +1794,6 @@ static int goku_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	}
 	dev->regs = (struct goku_udc_regs __iomem *) base;
 
-	pci_set_drvdata(pdev, dev);
 	INFO(dev, "%s\n", driver_desc);
 	INFO(dev, "version: " DRIVER_VERSION " %s\n", dmastr());
 	INFO(dev, "irq %d, pci mem %p\n", pdev->irq, base);
-- 
2.26.2