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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Peter Chen <peter.chen@kernel.org>,
        Andrey Strachuk <strochuk@ispras.ru>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 532/779] usb: cdns3: change place of priv_ep assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable()
Date:   Mon, 15 Aug 2022 20:02:56 +0200
Message-Id: <20220815180400.033429209@linuxfoundation.org>
In-Reply-To: <20220815180337.130757997@linuxfoundation.org>
References: <20220815180337.130757997@linuxfoundation.org>
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From: Andrey Strachuk <strochuk@ispras.ru>

[ Upstream commit c3ffc9c4ca44bfe9562166793d133e1fb0630ea6 ]

If 'ep' is NULL, result of ep_to_cdns3_ep(ep) is invalid pointer
and its dereference with priv_ep->cdns3_dev may cause panic.

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

Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Andrey Strachuk <strochuk@ispras.ru>
Link: https://lore.kernel.org/r/20220718160052.4188-1-strochuk@ispras.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/cdns3/cdns3-gadget.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index d6d515d598dc..e0cf62e65075 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2281,14 +2281,15 @@ static int cdns3_gadget_ep_enable(struct usb_ep *ep,
 	int val;
 
 	priv_ep = ep_to_cdns3_ep(ep);
-	priv_dev = priv_ep->cdns3_dev;
-	comp_desc = priv_ep->endpoint.comp_desc;
 
 	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
 		dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
 		return -EINVAL;
 	}
 
+	comp_desc = priv_ep->endpoint.comp_desc;
+	priv_dev = priv_ep->cdns3_dev;
+
 	if (!desc->wMaxPacketSize) {
 		dev_err(priv_dev->dev, "usbss: missing wMaxPacketSize\n");
 		return -EINVAL;
@@ -2596,7 +2597,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
 			    struct usb_request *request)
 {
 	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
-	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+	struct cdns3_device *priv_dev;
 	struct usb_request *req, *req_temp;
 	struct cdns3_request *priv_req;
 	struct cdns3_trb *link_trb;
@@ -2607,6 +2608,8 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
 	if (!ep || !request || !ep->desc)
 		return -EINVAL;
 
+	priv_dev = priv_ep->cdns3_dev;
+
 	spin_lock_irqsave(&priv_dev->lock, flags);
 
 	priv_req = to_cdns3_request(request);
-- 
2.35.1