On Sun, Oct 18, 2026 at 08:48:38PM +0100, David Laight wrote:
> On Sun, 18 Oct 2026 15:24:41 -0400
> "Michael S. Tsirkin" <[email protected]> wrote:
>
> > On Thu, Oct 15, 2026 at 03:23:45PM +0800, Haoran Wang wrote:
> > > I'd like to report an issue in drivers/vhost/vringh.c:1216 (function
> > > getu16_iotlb), found via static analysis of Linux 7.0.11 and verified
> > > against the 7.2.10 source tree. I have reproduced the leak on an
> > > unmodified 7.2.10 kernel.
> >
> >
> > This should fix it I think? Can you confirm pls?
> >
> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> > ---
> > drivers/vhost/vringh.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
> > index 9066f9f12ba1..4b097170bd36 100644
> > --- a/drivers/vhost/vringh.c
> > +++ b/drivers/vhost/vringh.c
> > @@ -1213,7 +1213,11 @@ static inline int getu16_iotlb(const struct vringh
> > *vrh,
> > return ret;
> >
> > if (vrh->use_va) {
> > - ret = __get_user(tmp, (__virtio16 __user
> > *)ivec.iov.iovec[0].iov_base);
> > + __virtio16 __user *uaddr = ivec.iov.iovec[0].iov_base;
> > +
> > + if (!access_ok(uaddr, sizeof(*p)))
> > + return -EFAULT;
> > + ret = __get_user(tmp, uaddr);
>
> Can't that be a normal get_user() call?
>
> David
Ugh, actually no. This is called under local_bh_disable.
get_user would splat on might_sleep.
> > if (ret)
> > return ret;
> > } else {
> > @@ -1251,7 +1255,11 @@ static inline int putu16_iotlb(const struct vringh
> > *vrh,
> > tmp = cpu_to_vringh16(vrh, val);
> >
> > if (vrh->use_va) {
> > - ret = __put_user(tmp, (__virtio16 __user
> > *)ivec.iov.iovec[0].iov_base);
> > + __virtio16 __user *uaddr = ivec.iov.iovec[0].iov_base;
> > +
> > + if (!access_ok(uaddr, sizeof(*p)))
> > + return -EFAULT;
> > + ret = __put_user(tmp, uaddr);
> > if (ret)
> > return ret;
> > } else {
> >
> >
