[PATCH 4.18 120/150] vhost: Fix Spectre V1 vulnerability

2018-11-02 Thread Greg Kroah-Hartman
4.18-stable review patch.  If anyone has any objections, please let me know.

--

From: Jason Wang 

[ 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 
Cc: Josh Poimboeuf 
Cc: Andrea Arcangeli 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman 
---
 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 
 #include 
 #include 
+#include 
 
 #include "vhost.h"
 
@@ -1362,6 +1363,7 @@ 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(>mutex);




[PATCH 4.18 120/150] vhost: Fix Spectre V1 vulnerability

2018-11-02 Thread Greg Kroah-Hartman
4.18-stable review patch.  If anyone has any objections, please let me know.

--

From: Jason Wang 

[ 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 
Cc: Josh Poimboeuf 
Cc: Andrea Arcangeli 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman 
---
 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 
 #include 
 #include 
+#include 
 
 #include "vhost.h"
 
@@ -1362,6 +1363,7 @@ 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(>mutex);