| Message ID | 20130707112653.GA31232@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: "Michael S. Tsirkin" <mst@redhat.com> Date: Sun, 7 Jul 2013 14:26:53 +0300 > vhost_net_ubuf_put_and_wait has a confusing name: > it will actually also free it's argument. > Thus since commit 1280c27f8e29acf4af2da914e80ec27c3dbd5c01 > "vhost-net: flush outstanding DMAs on memory change" > vhost_net_flush tries to use the argument after passing it > to vhost_net_ubuf_put_and_wait, this results > in use after free. > To fix, don't free the argument in vhost_net_ubuf_put_and_wait, > add an new API for callers that want to free ubufs. > > Acked-by: Asias He <asias@redhat.com> > Acked-by: Jason Wang <jasowang@redhat.com> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Applied and queued up for -stable. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index f80d3dd..8ca5ac7 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -150,6 +150,11 @@ static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs) { kref_put(&ubufs->kref, vhost_net_zerocopy_done_signal); wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount)); +} + +static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs) +{ + vhost_net_ubuf_put_and_wait(ubufs); kfree(ubufs); } @@ -948,7 +953,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) mutex_unlock(&vq->mutex); if (oldubufs) { - vhost_net_ubuf_put_and_wait(oldubufs); + vhost_net_ubuf_put_wait_and_free(oldubufs); mutex_lock(&vq->mutex); vhost_zerocopy_signal_used(n, vq); mutex_unlock(&vq->mutex); @@ -966,7 +971,7 @@ err_used: rcu_assign_pointer(vq->private_data, oldsock); vhost_net_enable_vq(n, vq); if (ubufs) - vhost_net_ubuf_put_and_wait(ubufs); + vhost_net_ubuf_put_wait_and_free(ubufs); err_ubufs: fput(sock->file); err_vq:
vhost_net_ubuf_put_and_wait has a confusing name: it will actually also free it's argument. Thus since commit 1280c27f8e29acf4af2da914e80ec27c3dbd5c01 "vhost-net: flush outstanding DMAs on memory change" vhost_net_flush tries to use the argument after passing it to vhost_net_ubuf_put_and_wait, this results in use after free. To fix, don't free the argument in vhost_net_ubuf_put_and_wait, add an new API for callers that want to free ubufs. Acked-by: Asias He <asias@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- Please review, and queue for 3.11 and stable. Changes from v2: - rebased to net/master Changes from v1: - tweak commit message drivers/vhost/net.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)