4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jason Wang jasowang@redhat.com
[ 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@redhat.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Andrea Arcangeli aarcange@redhat.com Signed-off-by: Jason Wang jasowang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/vhost/vhost.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -30,6 +30,7 @@ #include <linux/sched/mm.h> #include <linux/sched/signal.h> #include <linux/interval_tree_generic.h> +#include <linux/nospec.h>
#include "vhost.h"
@@ -1397,6 +1398,7 @@ 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);