On 2016年12月06日 10:10, Andy Lutomirski wrote:
With CONFIG_VMAP_STACK=y, virtnet_set_mac_address() can be passed a
pointer to the stack and it will OOPS. Copy the address to the heap
to prevent the crash.
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Reported-by: zbyszek@xxxxxxxxx
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
Very lightly tested.
drivers/net/virtio_net.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7276d5a95bd0..cbf1c613c67a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -969,12 +969,17 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
struct virtnet_info *vi = netdev_priv(dev);
struct virtio_device *vdev = vi->vdev;
int ret;
- struct sockaddr *addr = p;
+ struct sockaddr *addr;
struct scatterlist sg;
- ret = eth_prepare_mac_addr_change(dev, p);
+ addr = kmalloc(sizeof(*addr), GFP_KERNEL);
+ if (!addr)
+ return -ENOMEM;
+ memcpy(addr, p, sizeof(*addr));
+
+ ret = eth_prepare_mac_addr_change(dev, addr);
if (ret)
- return ret;
+ goto out;
if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
sg_init_one(&sg, addr->sa_data, dev->addr_len);
@@ -982,7 +987,8 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
dev_warn(&vdev->dev,
"Failed to set mac address by vq command.\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
@@ -996,8 +1002,11 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
}
eth_commit_mac_addr_change(dev, p);
+ ret = 0;
- return 0;
+out:
+ kfree(addr);
+ return ret;
}
static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
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