Re: [PATCH v2] hw/net/can: sja1000 fix buff2frame_bas and buff2frame_pel when dlc is out of std CAN 8 bytes

[Jason Wang]

在 2021/7/29 下午8:48, Philippe Mathieu-Daudé 写道:
> "hw/net/can: sja1000 fix buff2frame* when dlc is out of std CAN 8 bytes"
>
> On 7/29/21 2:33 PM, Pavel Pisa wrote:
> > Problem reported by openEuler fuzz-sig group.
> >
> > The buff2frame_bas function (hw\net\can\can_sja1000.c)
> > infoleak(qemu5.x~qemu6.x) or stack-overflow(qemu 4.x).
> Cc: qemu-stable@nongnu.org
>
> > Reported-by: Qiang Ning <ningqiang1@huawei.com>
> > Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>


Applied.

Thanks


> > ---
> >   hw/net/can/can_sja1000.c | 8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/hw/net/can/can_sja1000.c b/hw/net/can/can_sja1000.c
> > index 42d2f99dfb..34eea684ce 100644
> > --- a/hw/net/can/can_sja1000.c
> > +++ b/hw/net/can/can_sja1000.c
> > @@ -275,6 +275,10 @@ static void buff2frame_pel(const uint8_t *buff, 
> > qemu_can_frame *frame)
> >       }
> >       frame->can_dlc = buff[0] & 0x0f;
> >   
> > +    if (frame->can_dlc > 8) {
> > +        frame->can_dlc = 8;
> > +    }
> > +
> >       if (buff[0] & 0x80) { /* Extended */
> >           frame->can_id |= QEMU_CAN_EFF_FLAG;
> >           frame->can_id |= buff[1] << 21; /* ID.28~ID.21 */
> > @@ -311,6 +315,10 @@ static void buff2frame_bas(const uint8_t *buff, 
> > qemu_can_frame *frame)
> >       }
> >       frame->can_dlc = buff[1] & 0x0f;
> >   
> > +    if (frame->can_dlc > 8) {
> > +        frame->can_dlc = 8;
> > +    }
> > +
> >       for (i = 0; i < frame->can_dlc; i++) {
> >           frame->data[i] = buff[2 + i];
> >       }