Re: [V2 PATCH] usb: mtu3: fix NULL pointer dereference
On Thu, 2020-07-09 at 09:40 +0300, Felipe Balbi wrote: > Chunfeng Yun writes: > > > Some pointers are dereferenced before successful checks. > > > > Reported-by: Markus Elfring > > Signed-off-by: Chunfeng Yun > > do you need a Fixes tag here? Perhaps a Cc stable too? It will not cause somes issues, I think no need add it. According to Greg's comment, I guess he means no need check these pointers at all, so I'll send a new version to remove checks. Thank you >
Re: [V2 PATCH] usb: mtu3: fix NULL pointer dereference
Hi,
Chunfeng Yun writes:
>> > @@ -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;
>>
>> Same here, how can that ever happen?
> Maybe when the class driver has something wrong:)
>
> You mean it's better to remove these unnecessary checks?
if we need those checks, I'd rather have them at a central location,
such as udc/core.c. But, as Greg mentioned, the kernel doesn't call
these with NULL pointers.
--
balbi
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Re: [V2 PATCH] usb: mtu3: fix NULL pointer dereference
Chunfeng Yun writes: > Some pointers are dereferenced before successful checks. > > Reported-by: Markus Elfring > Signed-off-by: Chunfeng Yun do you need a Fixes tag here? Perhaps a Cc stable too? -- balbi signature.asc Description: PGP signature
Re: [V2 PATCH] usb: mtu3: fix NULL pointer dereference
On Wed, 2020-07-01 at 13:58 +0200, Greg Kroah-Hartman wrote:
> On Tue, Jun 30, 2020 at 03:42:22PM +0800, Chunfeng Yun wrote:
> > Some pointers are dereferenced before successful checks.
> >
> > Reported-by: Markus Elfring
> > Signed-off-by: Chunfeng Yun
> > ---
> > 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;
>
> How will either of those ever be NULL? The kernel will not call this
> function with either of them being NULL, right?
Yes, I find all class drivers already ensure they are not NULL.
>
> > +
> > + 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;
>
> Same here, how can that ever happen?
Maybe when the class driver has something wrong:)
You mean it's better to remove these unnecessary checks?
Thanks
>
> >
> > + mep = to_mtu3_ep(ep);
> > + mtu = mep->mtu;
> > +
> > dev_dbg(mtu->dev, "%s : %s...", __func__, ep->name);
> >
> > spin_lock_irqsave(>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;
>
> Again, same here.
>
> thanks,
>
> greg k-h
Re: [V2 PATCH] usb: mtu3: fix NULL pointer dereference
On Tue, Jun 30, 2020 at 03:42:22PM +0800, Chunfeng Yun wrote:
> Some pointers are dereferenced before successful checks.
>
> Reported-by: Markus Elfring
> Signed-off-by: Chunfeng Yun
> ---
> 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;
How will either of those ever be NULL? The kernel will not call this
function with either of them being NULL, right?
> +
> + 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;
Same here, how can that ever happen?
>
> + mep = to_mtu3_ep(ep);
> + mtu = mep->mtu;
> +
> dev_dbg(mtu->dev, "%s : %s...", __func__, ep->name);
>
> spin_lock_irqsave(>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;
Again, same here.
thanks,
greg k-h
[V2 PATCH] usb: mtu3: fix NULL pointer dereference
Some pointers are dereferenced before successful checks.
Reported-by: Markus Elfring
Signed-off-by: Chunfeng Yun
---
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(>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
