From:   Anastasia Belova <abelova@astralinux.ru>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Anastasia Belova <abelova@astralinux.ru>,
        Jakob Koschel <jakobkoschel@gmail.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        lvc-project@linuxtesting.org
Subject: [PATCH] goku_udc: Add check for NULL in goku_irq
Date:   Fri,  3 Feb 2023 13:18:28 +0300
Message-Id: <20230203101828.14799-1-abelova@astralinux.ru>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Before dereferencing dev->driver check it for NULL.

If an interrupt handler is called after assigning
NULL to dev->driver, but before resetting dev->int_enable,
NULL-pointer will be dereferenced.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
---
 drivers/usb/gadget/udc/goku_udc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/goku_udc.c b/drivers/usb/gadget/udc/g=
oku_udc.c
index bdc56b24b5c9..896bba8b47f1 100644
--- a/drivers/usb/gadget/udc/goku_udc.c
+++ b/drivers/usb/gadget/udc/goku_udc.c
@@ -1616,8 +1616,9 @@ static irqreturn_t goku_irq(int irq, void *_dev)
 pm_next:
 		if (stat & INT_USBRESET) {		/* hub reset done */
 			ACK(INT_USBRESET);
-			INFO(dev, "USB reset done, gadget %s\n",
-				dev->driver->driver.name);
+			if (dev->driver)
+				INFO(dev, "USB reset done, gadget %s\n",
+					dev->driver->driver.name);
 		}
 		// and INT_ERR on some endpoint's crc/bitstuff/... problem
 	}
--=20
2.30.2