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authorSi-Wei Liu <si-wei.liu@oracle.com>2022-01-15 03:28:01 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-03-16 16:23:35 +0300
commite7e118416465f2ba8b55007e5b789823e101421e (patch)
treefa38a79a5511c5f7afa607399e3eb65ba5f2d958 /drivers/vdpa
parentf96dc3adb9a97b8f3dfdb88796483491a3006b71 (diff)
downloadlinux-e7e118416465f2ba8b55007e5b789823e101421e.tar.xz
vdpa/mlx5: add validation for VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command
[ Upstream commit ed0f849fc3a63ed2ddf5e72cdb1de3bdbbb0f8eb ] When control vq receives a VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command request from the driver, presently there is no validation against the number of queue pairs to configure, or even if multiqueue had been negotiated or not is unverified. This may lead to kernel panic due to uninitialized resource for the queues were there any bogus request sent down by untrusted driver. Tie up the loose ends there. Fixes: 52893733f2c5 ("vdpa/mlx5: Add multiqueue support") Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com> Link: https://lore.kernel.org/r/1642206481-30721-4-git-send-email-si-wei.liu@oracle.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eli Cohen <elic@nvidia.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/vdpa')
-rw-r--r--drivers/vdpa/mlx5/net/mlx5_vnet.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 1afbda216df5..902aad29456f 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1529,11 +1529,27 @@ static virtio_net_ctrl_ack handle_ctrl_mq(struct mlx5_vdpa_dev *mvdev, u8 cmd)
switch (cmd) {
case VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET:
+ /* This mq feature check aligns with pre-existing userspace
+ * implementation.
+ *
+ * Without it, an untrusted driver could fake a multiqueue config
+ * request down to a non-mq device that may cause kernel to
+ * panic due to uninitialized resources for extra vqs. Even with
+ * a well behaving guest driver, it is not expected to allow
+ * changing the number of vqs on a non-mq device.
+ */
+ if (!MLX5_FEATURE(mvdev, VIRTIO_NET_F_MQ))
+ break;
+
read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->riov, (void *)&mq, sizeof(mq));
if (read != sizeof(mq))
break;
newqps = mlx5vdpa16_to_cpu(mvdev, mq.virtqueue_pairs);
+ if (newqps < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
+ newqps > mlx5_vdpa_max_qps(mvdev->max_vqs))
+ break;
+
if (ndev->cur_num_vqs == 2 * newqps) {
status = VIRTIO_NET_OK;
break;