[dpdk-stable] [16.11 LTS PATCH] vhost: fix vring requests validation broken if no FD
Maxime Coquelin
maxime.coquelin at redhat.com
Thu Nov 14 16:16:01 CET 2019
From: Zhike Wang <wangzk320 at 163.com>
When VHOST_USER_VRING_NOFD_MASK is set, the fd_num is 0,
so validate_msg_fds() will return error. In this case,
the negotiation of vring message between vhost user front end and
back end would fail, and as a result, vhost user link could NOT be up.
How to reproduce:
1.Run dpdk testpmd insides VM, which locates at host with ovs+dpdk.
2.Notice that inside ovs there are endless logs regarding failure to
handle VHOST_USER_SET_VRING_CALL, and link of vm could NOT be up.
Fixes: 1bf11cfb7c7c ("vhost: fix possible denial of service by leaking FDs")
Cc: stable at dpdk.org
Signed-off-by: Zhike Wang <wangzk320 at 163.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
Backport not tested yet.
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 a6ab131543..5aeb0c1691 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1078,6 +1078,7 @@ vhost_user_msg_handler(int vid, int fd)
struct VhostUserMsg msg;
int ret;
int unlock_required = 0;
+ int expected_fds;
dev = get_device(vid);
if (dev == NULL)
@@ -1236,12 +1237,16 @@ vhost_user_msg_handler(int vid, int fd)
break;
case VHOST_USER_SET_VRING_KICK:
- if (validate_msg_fds(&msg, 1) != 0)
+ expected_fds =
+ (msg.payload.u64 & VHOST_USER_VRING_NOFD_MASK) ? 0 : 1;
+ if (validate_msg_fds(&msg, expected_fds) != 0)
return -1;
ret = vhost_user_set_vring_kick(dev, &msg);
break;
case VHOST_USER_SET_VRING_CALL:
+ expected_fds =
+ (msg.payload.u64 & VHOST_USER_VRING_NOFD_MASK) ? 0 : 1;
if (validate_msg_fds(&msg, 1) != 0)
return -1;
@@ -1249,6 +1254,8 @@ vhost_user_msg_handler(int vid, int fd)
break;
case VHOST_USER_SET_VRING_ERR:
+ expected_fds =
+ (msg.payload.u64 & VHOST_USER_VRING_NOFD_MASK) ? 0 : 1;
if (validate_msg_fds(&msg, 1) != 0)
return -1;
--
2.21.0
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