On Tue, Mar 02, 2021 at 10:19:11PM +0100, Stefan Richter wrote:
> On Mar 02 Dan Carpenter wrote:
> > In TCODE_STREAM_DATA mode, on 32bit systems, the "sizeof(*e) +
> > request->length" operation can overflow leading to memory corruption.
> >
> > Fixes: 18e9b10fcdc0 ("firewire: cdev: add closure to async stream ioctl")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > ---
> > drivers/firewire/core-cdev.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
> > index fb6c651214f3..314de0384035 100644
> > --- a/drivers/firewire/core-cdev.c
> > +++ b/drivers/firewire/core-cdev.c
> > @@ -587,6 +587,9 @@ static int init_request(struct client *client,
> > request->length < 4)
> > return -EINVAL;
> >
> > + if (request->length > ULONG_MAX - sizeof(*e))
> > + return -EINVAL;
> > +
> > e = kmalloc(sizeof(*e) + request->length, GFP_KERNEL);
> > if (e == NULL)
> > return -ENOMEM;
>
> There is already a length check for asynchronous stream requests.
> It happens in ioctl_send_stream_packet().
Oh, yeah. You're right. I should have looked more carefully. Sorry.
regards,
dan carpenter
