On Fri, Sep 18, 2015 at 12:49:07PM +0200, Christian Borntraeger wrote:
> Am 18.09.2015 um 12:41 schrieb Michael S. Tsirkin:
> > Upon TUNSETSNDBUF, macvtap reads the requested sndbuf size into
> > a local variable u.
> > commit 39ec7de7092b ("macvtap: fix uninitialized access on
> > TUNSETIFF") changed its type to u16 (which is the right thing to
> > do for all other macvtap ioctls), breaking all values > 64k.
> >
> > The value of TUNSETSNDBUF is actually a signed 32 bit integer, so
> > the right thing to do is to read it into an int.
> >
> > Cc: David S. Miller <da...@davemloft.net>
> > Fixes: 39ec7de7092b ("macvtap: fix uninitialized access on TUNSETIFF")
> > Reported-by: Mark A. Peloquin
> > Bisected-by: Matthew Rosato <mjros...@linux.vnet.ibm.com>
> > Reported-by: Christian Borntraeger <borntrae...@de.ibm.com>
> > Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
>
> You can add
> Tested-by: Matthew Rosato <mjros...@linux.vnet.ibm.com>
> as this looks identical to an early version of my patch which was tested,
> by Matt. (I send you the other version that changes back u as I felt that
> u and up are named to identify unsigned)
>
> and please add
> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com>
>
> what about
> CC: sta...@vger.kernel.org
>
> Christian
David Miller adds that himself for netdev patches.
> > ---
> >
> > This patch probably makes sense on stable.
> >
> > drivers/net/macvtap.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
> > index edd7734..248478c 100644
> > --- a/drivers/net/macvtap.c
> > +++ b/drivers/net/macvtap.c
> > @@ -1111,10 +1111,10 @@ static long macvtap_ioctl(struct file *file,
> > unsigned int cmd,
> > return 0;
> >
> > case TUNSETSNDBUF:
> > - if (get_user(u, up))
> > + if (get_user(s, sp))
> > return -EFAULT;
> >
> > - q->sk.sk_sndbuf = u;
> > + q->sk.sk_sndbuf = s;
> > return 0;
> >
> > case TUNGETVNETHDRSZ:
> >
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