From 95e1f29c26777ee36456e340ed9c2b07472add28 Mon Sep 17 00:00:00 2001
From: Xiaolong Ye <xiaolong.ye@intel.com>
Date: Wed, 8 Apr 2020 15:31:35 +0800
Subject: vhost: fix potential memory space leak

A malicious container which has direct access to the vhost-user socket
can keep sending VHOST_USER_GET_INFLIGHT_FD messages which may cause
leaking resources until resulting a DOS. Fix it by unmapping the
dev->inflight_info->addr before assigning new mapped addr to it.

Fixes: d87f1a1cb7b6 ("vhost: support inflight info sharing")

This issue has been assigned CVE-2020-10726

Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index d196142..2a4ba20 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1440,6 +1440,11 @@ vhost_user_get_inflight_fd(struct virtio_net **pdev,
 	}
 	memset(addr, 0, mmap_size);
 
+	if (dev->inflight_info->addr) {
+		munmap(dev->inflight_info->addr, dev->inflight_info->size);
+		dev->inflight_info->addr = NULL;
+	}
+
 	dev->inflight_info->addr = addr;
 	dev->inflight_info->size = msg->payload.inflight.mmap_size = mmap_size;
 	dev->inflight_info->fd = msg->fds[0] = fd;
@@ -1524,8 +1529,10 @@ vhost_user_set_inflight_fd(struct virtio_net **pdev, VhostUserMsg *msg,
 		}
 	}
 
-	if (dev->inflight_info->addr)
+	if (dev->inflight_info->addr) {
 		munmap(dev->inflight_info->addr, dev->inflight_info->size);
+		dev->inflight_info->addr = NULL;
+	}
 
 	addr = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
 		    fd, mmap_offset);
-- 
cgit v1.0

