On Mon, Apr 28, 2014 at 01:35:19PM +0200, walter harms wrote:
>
>
> Am 28.04.2014 12:58, schrieb Dan Carpenter:
> > The obd_ioctl_getdata() function caps "data->ioc_len" at
> > OBD_MAX_IOCTL_BUFFER and then calls this obd_ioctl_is_invalid() to check
> > that the other values inside data are valid.
> >
> > There are several lengths inside data but when they are added together
> > they must not be larger than "data->ioc_len". The checks against
> > "(data->ioc_inllen1 > (1<<30))" are supposed to ensure that the addition
> > does not have an integer overflow. But "(1<<30) * 4" actually can
> > overflow 32 bits, so the checks are insufficient.
> >
> > I have changed it to "> OBD_MAX_IOCTL_BUFFER" instead.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > ---
> > v2: Updated the error messages as Walter Harms pointed out.
> >
> > diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
> > index bdc9812..3c26bbd 100644
> > --- a/drivers/staging/lustre/lustre/include/lustre_lib.h
> > +++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
> > @@ -179,24 +179,25 @@ static inline int obd_ioctl_packlen(struct obd_ioctl_data *data)
> >
> > static inline int obd_ioctl_is_invalid(struct obd_ioctl_data *data)
> > {
> > - if (data->ioc_len > (1<<30)) {
> > - CERROR("OBD ioctl: ioc_len larger than 1<<30\n");
> > + if (data->ioc_len > OBD_MAX_IOCTL_BUFFER) {
> > + CERROR("OBD ioctl: ioc_len larger than %d\n",
> > + OBD_MAX_IOCTL_BUFFER);
> > return 1;
> > }
> > - if (data->ioc_inllen1 > (1<<30)) {
> > - CERROR("OBD ioctl: ioc_inllen1 larger than 1<<30\n");
> > + if (data->ioc_inllen1 > OBD_MAX_IOCTL_BUFFER) {
> > + CERROR("OBD ioctl: ioc_inllen1 larger than ioc_len\n");
> > return 1;
> > }
>
> The error mention ioc_len the compare is OBD_MAX_IOCTL_BUFFER ?
> Is that intentional ?
Yep.
regards,
dan carpenter
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