[PATCH] usb: mtu3: Fix possible use-before-initialization bug
Chunfeng Yun (云春峰)
Chunfeng.Yun at mediatek.com
Tue Jul 11 01:48:35 PDT 2023
On Mon, 2023-07-10 at 08:25 +0200, Herve Codina wrote:
>
> External email : Please do not click links or open attachments until
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> Hi Yu,
>
> On Sun, 9 Jul 2023 17:48:15 -0700
> Yu Hao <yhao016 at ucr.edu> wrote:
>
> > Hi Hervé,
> >
> > Thanks for the comments. How about this patch?
> > ---
> > drivers/usb/mtu3/mtu3_gadget_ep0.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/usb/mtu3/mtu3_gadget_ep0.c
> > b/drivers/usb/mtu3/mtu3_gadget_ep0.c
> > index e4fd1bb14a55..af2884943c2a 100644
> > --- a/drivers/usb/mtu3/mtu3_gadget_ep0.c
> > +++ b/drivers/usb/mtu3/mtu3_gadget_ep0.c
> > @@ -600,7 +600,7 @@ static void ep0_tx_state(struct mtu3 *mtu)
> > mtu3_readl(mtu->mac_base, U3D_EP0CSR));
> > }
> >
> > -static void ep0_read_setup(struct mtu3 *mtu, struct
> usb_ctrlrequest *setup)
> > +static int ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest
> *setup)
> > {
> > struct mtu3_request *mreq;
> > u32 count;
> > @@ -608,6 +608,8 @@ static void ep0_read_setup(struct mtu3 *mtu,
> > struct usb_ctrlrequest *setup)
> >
> > csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
> > count = mtu3_readl(mtu->mac_base, U3D_RXCOUNT0);
> > + if (count == 0)
> > + return -EINVAL;
>
> 'count' should be tested against sizeof(*setup). Indeed, we need to
> have a
> setup data packet in the fifo.
>
> What do you think about:
> if (count < sizef(*setup))
> return -EINVAL;
before call this function, already check the data length in fifo, it
should be 8 bytes.
see mtu3_ep0_isr(), about line 761.
I think no need this patch
Thanks a lot
>
> >
> > ep0_read_fifo(mtu->ep0, (u8 *)setup, count);
> >
> > @@ -642,7 +644,8 @@ __acquires(mtu->lock)
> > struct mtu3_request *mreq;
> > int handled = 0;
> >
> > - ep0_read_setup(mtu, &setup);
> > + if (ep0_read_setup(mtu, &setup))
> > + return -EINVAL;
>
> Forward the error code to the caller ?
>
> ret = ep0_read_setup(mtu, &setup)
> if (ret < 0)
> return ret;
>
>
> > trace_mtu3_handle_setup(&setup);
> >
> > if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
> > @@ -764,7 +767,9 @@ irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu)
> > break;
> > }
> >
> > - ep0_handle_setup(mtu);
> > + if (ep0_handle_setup(mtu))
> > + break;
> > +
>
> Ok
>
> > ret = IRQ_HANDLED;
> > break;
> > default:
>
> Be careful, your patch is wrongly indented.
> tabs replaced by 4 spaces. You need to keep tabs.
>
> Regards,
> Hervé Codina
>
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