diff options
| author | Andy Lutomirski <luto@kernel.org> | 2016-12-05 18:10:58 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-06 11:38:43 -0500 |
| commit | e37e2ff350a321ad9c36b588e76f34fbba305be6 (patch) | |
| tree | ea9cc96f7d589fe209cccd7af95047d5e631d423 | |
| parent | dcb17d22e1c2cd72e72190c736349a675362b3bc (diff) | |
| download | lwn-e37e2ff350a321ad9c36b588e76f34fbba305be6.tar.gz lwn-e37e2ff350a321ad9c36b588e76f34fbba305be6.zip | |
virtio-net: Fix DMA-from-the-stack in virtnet_set_mac_address()
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@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Laura Abbott <labbott@redhat.com>
Reported-by: zbyszek@in.waw.pl
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/virtio_net.c | 19 |
1 files 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, |