From: Xuan Ding <xuan.ding@intel.com>
Date: Mon, 18 May 2020 13:17:04 +0000 (+0100)
Subject: vhost: fix potential fd leak
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=e7debf602633feb26227cdc8cc7fdd1b1b40946a;p=dpdk.git

vhost: fix potential fd leak

Vhost will create temporary file when receiving VHOST_USER_GET_INFLIGHT_FD
message. Malicious guest can send endless this message to drain out the
resource of host.

When receiving VHOST_USER_GET_INFLIGHT_FD message repeatedly, closing the
file created during the last handling of this message.

CVE-2020-10726
Fixes: d87f1a1cb7b666550 ("vhost: support inflight info sharing")
Cc: stable@dpdk.org

Signed-off-by: Xuan Ding <xuan.ding@intel.com>
Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 9d25490fb3..84bebad792 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -206,7 +206,7 @@ vhost_backend_cleanup(struct virtio_net *dev)
 			dev->inflight_info->addr = NULL;
 		}
 
-		if (dev->inflight_info->fd > 0) {
+		if (dev->inflight_info->fd >= 0) {
 			close(dev->inflight_info->fd);
 			dev->inflight_info->fd = -1;
 		}
@@ -1417,6 +1417,7 @@ vhost_user_get_inflight_fd(struct virtio_net **pdev,
 				"failed to alloc dev inflight area\n");
 			return RTE_VHOST_MSG_RESULT_ERR;
 		}
+		dev->inflight_info->fd = -1;
 	}
 
 	num_queues = msg->payload.inflight.num_queues;
@@ -1447,6 +1448,11 @@ vhost_user_get_inflight_fd(struct virtio_net **pdev,
 		dev->inflight_info->addr = NULL;
 	}
 
+	if (dev->inflight_info->fd >= 0) {
+		close(dev->inflight_info->fd);
+		dev->inflight_info->fd = -1;
+	}
+
 	dev->inflight_info->addr = addr;
 	dev->inflight_info->size = msg->payload.inflight.mmap_size = mmap_size;
 	dev->inflight_info->fd = msg->fds[0] = fd;
@@ -1529,6 +1535,7 @@ vhost_user_set_inflight_fd(struct virtio_net **pdev, VhostUserMsg *msg,
 				"failed to alloc dev inflight area\n");
 			return RTE_VHOST_MSG_RESULT_ERR;
 		}
+		dev->inflight_info->fd = -1;
 	}
 
 	if (dev->inflight_info->addr) {
@@ -1543,8 +1550,10 @@ vhost_user_set_inflight_fd(struct virtio_net **pdev, VhostUserMsg *msg,
 		return RTE_VHOST_MSG_RESULT_ERR;
 	}
 
-	if (dev->inflight_info->fd)
+	if (dev->inflight_info->fd >= 0) {
 		close(dev->inflight_info->fd);
+		dev->inflight_info->fd = -1;
+	}
 
 	dev->inflight_info->fd = fd;
 	dev->inflight_info->addr = addr;