On 09/19/16 20:25, P J P wrote: > From: Prasad J Pandit <p...@fedoraproject.org> > > virtio back end uses set of buffers to facilitate I/O operations. > If its size is too large, 'cpu_physical_memory_map' could return > a null address. This would result in a null dereference while > un-mapping descriptors. Add check to avoid it. > > Reported-by: Qinghao Tang <luodalon...@gmail.com> > Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> > --- > hw/virtio/virtio.c | 5 +++++ > 1 file changed, 5 insertions(+) > > Update per: > -> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg04329.html > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 15ee3a7..a4ebf8c 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -472,6 +472,11 @@ static void virtqueue_map_desc(unsigned int *p_num_sg, > hwaddr *addr, struct iove > } > > iov[num_sg].iov_base = cpu_physical_memory_map(pa, &len, is_write); > + if (!iov[num_sg].iov_base) { > + error_report("virtio: bogus descriptor or out of resources"); > + exit(1); > + } > + > iov[num_sg].iov_len = len; > addr[num_sg] = pa; > >
Reviewed-by: Laszlo Ersek <ler...@redhat.com>
