4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang <jasowang@xxxxxxxxxx> [ Upstream commit ff002269a4ee9c769dbf9365acef633ebcbd6cbe ] The idx in vhost_vring_ioctl() was controlled by userspace, hence a potential exploitation of the Spectre variant 1 vulnerability. Fixing this by sanitizing idx before using it to index d->vqs. Cc: Michael S. Tsirkin <mst@xxxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/vhost/vhost.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -28,6 +28,7 @@ #include <linux/module.h> #include <linux/sort.h> #include <linux/interval_tree_generic.h> +#include <linux/nospec.h> #include "vhost.h" @@ -1289,6 +1290,7 @@ long vhost_vring_ioctl(struct vhost_dev if (idx >= d->nvqs) return -ENOBUFS; + idx = array_index_nospec(idx, d->nvqs); vq = d->vqs[idx]; mutex_lock(&vq->mutex);
