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* [V2 PATCH] usb: mtu3: fix NULL pointer dereference
@ 2020-06-30  7:42 Chunfeng Yun
  2020-06-30 10:47 ` [PATCH v2] usb: mtu3: Fix NULL pointer dereferences Markus Elfring
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Chunfeng Yun @ 2020-06-30  7:42 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Felipe Balbi
  Cc: Matthias Brugger, Markus Elfring, Chunfeng Yun, linux-usb,
	linux-arm-kernel, linux-mediatek, linux-kernel

Some pointers are dereferenced before successful checks.

Reported-by: Markus Elfring <Markus.Elfring@web.de>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: nothing changed, but abandon another patch
---
 drivers/usb/mtu3/mtu3_gadget.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c
index f93732e..1689ca8 100644
--- a/drivers/usb/mtu3/mtu3_gadget.c
+++ b/drivers/usb/mtu3/mtu3_gadget.c
@@ -332,14 +332,21 @@ static int mtu3_gadget_queue(struct usb_ep *ep,
 
 static int mtu3_gadget_dequeue(struct usb_ep *ep, struct usb_request *req)
 {
-	struct mtu3_ep *mep = to_mtu3_ep(ep);
-	struct mtu3_request *mreq = to_mtu3_request(req);
+	struct mtu3_ep *mep;
+	struct mtu3_request *mreq;
 	struct mtu3_request *r;
+	struct mtu3 *mtu;
 	unsigned long flags;
 	int ret = 0;
-	struct mtu3 *mtu = mep->mtu;
 
-	if (!ep || !req || mreq->mep != mep)
+	if (!ep || !req)
+		return -EINVAL;
+
+	mep = to_mtu3_ep(ep);
+	mtu = mep->mtu;
+
+	mreq = to_mtu3_request(req);
+	if (mreq->mep != mep)
 		return -EINVAL;
 
 	dev_dbg(mtu->dev, "%s : req=%p\n", __func__, req);
@@ -373,8 +380,8 @@ static int mtu3_gadget_dequeue(struct usb_ep *ep, struct usb_request *req)
  */
 static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value)
 {
-	struct mtu3_ep *mep = to_mtu3_ep(ep);
-	struct mtu3 *mtu = mep->mtu;
+	struct mtu3_ep *mep;
+	struct mtu3 *mtu;
 	struct mtu3_request *mreq;
 	unsigned long flags;
 	int ret = 0;
@@ -382,6 +389,9 @@ static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value)
 	if (!ep)
 		return -EINVAL;
 
+	mep = to_mtu3_ep(ep);
+	mtu = mep->mtu;
+
 	dev_dbg(mtu->dev, "%s : %s...", __func__, ep->name);
 
 	spin_lock_irqsave(&mtu->lock, flags);
@@ -422,11 +432,12 @@ static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value)
 /* Sets the halt feature with the clear requests ignored */
 static int mtu3_gadget_ep_set_wedge(struct usb_ep *ep)
 {
-	struct mtu3_ep *mep = to_mtu3_ep(ep);
+	struct mtu3_ep *mep;
 
 	if (!ep)
 		return -EINVAL;
 
+	mep = to_mtu3_ep(ep);
 	mep->wedged = 1;
 
 	return usb_ep_set_halt(ep);
-- 
1.9.1

^ permalink raw reply	[flat|nested] 7+ messages in thread

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Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-30  7:42 [V2 PATCH] usb: mtu3: fix NULL pointer dereference Chunfeng Yun
2020-06-30 10:47 ` [PATCH v2] usb: mtu3: Fix NULL pointer dereferences Markus Elfring
2020-07-01 11:58 ` [V2 PATCH] usb: mtu3: fix NULL pointer dereference Greg Kroah-Hartman
2020-07-02  2:52   ` Chunfeng Yun
2020-07-09  6:42     ` Felipe Balbi
2020-07-09  6:40 ` Felipe Balbi
2020-07-09  7:05   ` Chunfeng Yun

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