diff mbox series

[v17.11,v2,3/4] vhost: fix possible denial of service on SET_VRING_NUM

Message ID 20191112151927.27418-3-maxime.coquelin@redhat.com (mailing list archive)
State Not Applicable, archived
Delegated to: Maxime Coquelin
Headers
Series [v17.11,v2,1/4] vhost: validate virtqueue size |

Commit Message

Maxime Coquelin Nov. 12, 2019, 3:19 p.m. UTC 
  vhost_user_set_vring_num() performs multiple allocations
without checking whether data were previously allocated.

It may cause a denial of service because of the memory leaks
that happen if a malicious vhost-user master keeps sending
VHOST_USER_SET_VRING_NUM request until the slave runs out
of memory.

This issue has been assigned CVE-2019-14818

Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 9773691097..781734e9e3 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -262,6 +262,8 @@  vhost_user_set_vring_num(struct virtio_net *dev,
 		vq->nr_zmbuf = 0;
 		vq->last_zmbuf_idx = 0;
 		vq->zmbuf_size = vq->size;
+		if (vq->zmbufs)
+			rte_free(vq->zmbufs);
 		vq->zmbufs = rte_zmalloc(NULL, vq->zmbuf_size *
 					 sizeof(struct zcopy_mbuf), 0);
 		if (vq->zmbufs == NULL) {
@@ -271,7 +273,8 @@  vhost_user_set_vring_num(struct virtio_net *dev,
 			dev->dequeue_zero_copy = 0;
 		}
 	}
-
+	if (vq->shadow_used_ring)
+		rte_free(vq->shadow_used_ring);
 	vq->shadow_used_ring = rte_malloc(NULL,
 				vq->size * sizeof(struct vring_used_elem),
 				RTE_CACHE_LINE_SIZE);
@@ -281,6 +284,8 @@  vhost_user_set_vring_num(struct virtio_net *dev,
 		return -1;
 	}
 
+	if (vq->batch_copy_elems)
+		rte_free(vq->batch_copy_elems);
 	vq->batch_copy_elems = rte_malloc(NULL,
 				vq->size * sizeof(struct batch_copy_elem),
 				RTE_CACHE_LINE_SIZE);