[dpdk-dev] [master PATCH v2 2/2] vhost: fix possible denial of service by leaking FDs
Maxime Coquelin
maxime.coquelin at redhat.com
Tue Nov 12 16:19:35 CET 2019
A malicious Vhost-user master could send in loop hand-crafted
vhost-user messages containing more file descriptors the
vhost-user slave expects. Doing so causes the application using
the vhost-user library to run out of FDs.
This issue has been assigned CVE-2019-14818
Fixes: 8f972312b8f4 ("vhost: support vhost-user")
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
lib/librte_vhost/vhost_user.c | 119 ++++++++++++++++++++++++++++++++--
1 file changed, 115 insertions(+), 4 deletions(-)
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 6d2431e604..049e37c6de 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -83,6 +83,36 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
static int read_vhost_message(int sockfd, struct VhostUserMsg *msg);
+static void
+close_msg_fds(struct VhostUserMsg *msg)
+{
+ int i;
+
+ for (i = 0; i < msg->fd_num; i++)
+ close(msg->fds[i]);
+}
+
+/*
+ * Ensure the expected number of FDs is received,
+ * close all FDs and return an error if this is not the case.
+ */
+static int
+validate_msg_fds(struct VhostUserMsg *msg, int expected_fds)
+{
+ if (msg->fd_num == expected_fds)
+ return 0;
+
+ RTE_LOG(ERR, VHOST_CONFIG,
+ " Expect %d FDs for request %s, received %d\n",
+ expected_fds,
+ vhost_message_str[msg->request.master],
+ msg->fd_num);
+
+ close_msg_fds(msg);
+
+ return -1;
+}
+
static uint64_t
get_blk_size(int fd)
{
@@ -179,18 +209,25 @@ vhost_backend_cleanup(struct virtio_net *dev)
*/
static int
vhost_user_set_owner(struct virtio_net **pdev __rte_unused,
- struct VhostUserMsg *msg __rte_unused,
+ struct VhostUserMsg *msg,
int main_fd __rte_unused)
{
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
return RTE_VHOST_MSG_RESULT_OK;
}
static int
vhost_user_reset_owner(struct virtio_net **pdev,
- struct VhostUserMsg *msg __rte_unused,
+ struct VhostUserMsg *msg,
int main_fd __rte_unused)
{
struct virtio_net *dev = *pdev;
+
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
vhost_destroy_device_notify(dev);
cleanup_device(dev, 0);
@@ -208,6 +245,9 @@ vhost_user_get_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct virtio_net *dev = *pdev;
uint64_t features = 0;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
rte_vhost_driver_get_features(dev->ifname, &features);
msg->payload.u64 = features;
@@ -227,6 +267,9 @@ vhost_user_get_queue_num(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct virtio_net *dev = *pdev;
uint32_t queue_num = 0;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
rte_vhost_driver_get_queue_num(dev->ifname, &queue_num);
msg->payload.u64 = (uint64_t)queue_num;
@@ -249,6 +292,9 @@ vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct rte_vdpa_device *vdpa_dev;
int did = -1;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
rte_vhost_driver_get_features(dev->ifname, &vhost_features);
if (features & ~vhost_features) {
RTE_LOG(ERR, VHOST_CONFIG,
@@ -331,6 +377,9 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
struct virtio_net *dev = *pdev;
struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
vq->size = msg->payload.state.num;
/* VIRTIO 1.0, 2.4 Virtqueues says:
@@ -718,6 +767,9 @@ vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct vhost_vring_addr *addr = &msg->payload.addr;
bool access_ok;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (dev->mem == NULL)
return RTE_VHOST_MSG_RESULT_ERR;
@@ -759,6 +811,9 @@ vhost_user_set_vring_base(struct virtio_net **pdev,
struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
uint64_t val = msg->payload.state.num;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (vq_is_packed(dev)) {
/*
* Bit[0:14]: avail index
@@ -920,6 +975,9 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
int populate;
int fd;
+ if (validate_msg_fds(msg, memory->nregions) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (memory->nregions > VHOST_MEMORY_MAX_NREGIONS) {
RTE_LOG(ERR, VHOST_CONFIG,
"too many memory regions (%u)\n", memory->nregions);
@@ -930,8 +988,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
RTE_LOG(INFO, VHOST_CONFIG,
"(%d) memory regions not changed\n", dev->vid);
- for (i = 0; i < memory->nregions; i++)
- close(msg->fds[i]);
+ close_msg_fds(msg);
return RTE_VHOST_MSG_RESULT_OK;
}
@@ -1074,6 +1131,10 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
"Failed to read qemu ack on postcopy set-mem-table\n");
goto err_mmap;
}
+
+ if (validate_msg_fds(&ack_msg, 0) != 0)
+ goto err_mmap;
+
if (ack_msg.request.master != VHOST_USER_SET_MEM_TABLE) {
RTE_LOG(ERR, VHOST_CONFIG,
"Bad qemu ack on postcopy set-mem-table (%d)\n",
@@ -1194,6 +1255,9 @@ vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct vhost_vring_file file;
struct vhost_virtqueue *vq;
+ if (validate_msg_fds(msg, 1) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
file.index = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
if (msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
file.fd = VIRTIO_INVALID_EVENTFD;
@@ -1215,6 +1279,9 @@ static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
struct VhostUserMsg *msg,
int main_fd __rte_unused)
{
+ if (validate_msg_fds(msg, 1) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (!(msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK))
close(msg->fds[0]);
RTE_LOG(INFO, VHOST_CONFIG, "not implemented\n");
@@ -1230,6 +1297,9 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct vhost_vring_file file;
struct vhost_virtqueue *vq;
+ if (validate_msg_fds(msg, 1) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
file.index = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
if (msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
file.fd = VIRTIO_INVALID_EVENTFD;
@@ -1286,6 +1356,9 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
uint64_t val;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
/* We have to stop the queue (virtio) if it is running. */
vhost_destroy_device_notify(dev);
@@ -1361,6 +1434,9 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
struct rte_vdpa_device *vdpa_dev;
int did = -1;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
RTE_LOG(INFO, VHOST_CONFIG,
"set queue enable: %d to qp idx: %d\n",
enable, index);
@@ -1391,6 +1467,9 @@ vhost_user_get_protocol_features(struct virtio_net **pdev,
struct virtio_net *dev = *pdev;
uint64_t features, protocol_features;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
rte_vhost_driver_get_features(dev->ifname, &features);
rte_vhost_driver_get_protocol_features(dev->ifname, &protocol_features);
@@ -1419,6 +1498,9 @@ vhost_user_set_protocol_features(struct virtio_net **pdev,
uint64_t protocol_features = msg->payload.u64;
uint64_t slave_protocol_features = 0;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
rte_vhost_driver_get_protocol_features(dev->ifname,
&slave_protocol_features);
if (protocol_features & ~slave_protocol_features) {
@@ -1445,6 +1527,9 @@ vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg,
uint64_t size, off;
void *addr;
+ if (validate_msg_fds(msg, 1) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (fd < 0) {
RTE_LOG(ERR, VHOST_CONFIG, "invalid log fd: %d\n", fd);
return RTE_VHOST_MSG_RESULT_ERR;
@@ -1508,6 +1593,9 @@ static int vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
struct VhostUserMsg *msg,
int main_fd __rte_unused)
{
+ if (validate_msg_fds(msg, 1) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
close(msg->fds[0]);
RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
@@ -1531,6 +1619,9 @@ vhost_user_send_rarp(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct rte_vdpa_device *vdpa_dev;
int did = -1;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
RTE_LOG(DEBUG, VHOST_CONFIG,
":: mac: %02x:%02x:%02x:%02x:%02x:%02x\n",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
@@ -1558,6 +1649,10 @@ vhost_user_net_set_mtu(struct virtio_net **pdev, struct VhostUserMsg *msg,
int main_fd __rte_unused)
{
struct virtio_net *dev = *pdev;
+
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (msg->payload.u64 < VIRTIO_MIN_MTU ||
msg->payload.u64 > VIRTIO_MAX_MTU) {
RTE_LOG(ERR, VHOST_CONFIG, "Invalid MTU size (%"PRIu64")\n",
@@ -1578,6 +1673,9 @@ vhost_user_set_req_fd(struct virtio_net **pdev, struct VhostUserMsg *msg,
struct virtio_net *dev = *pdev;
int fd = msg->fds[0];
+ if (validate_msg_fds(msg, 1) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (fd < 0) {
RTE_LOG(ERR, VHOST_CONFIG,
"Invalid file descriptor for slave channel (%d)\n",
@@ -1663,6 +1761,9 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg,
uint16_t i;
uint64_t vva, len;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
switch (imsg->type) {
case VHOST_IOTLB_UPDATE:
len = imsg->size;
@@ -1709,6 +1810,9 @@ vhost_user_set_postcopy_advise(struct virtio_net **pdev,
#ifdef RTE_LIBRTE_VHOST_POSTCOPY
struct uffdio_api api_struct;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
if (dev->postcopy_ufd == -1) {
@@ -1744,6 +1848,9 @@ vhost_user_set_postcopy_listen(struct virtio_net **pdev,
{
struct virtio_net *dev = *pdev;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
if (dev->mem && dev->mem->nregions) {
RTE_LOG(ERR, VHOST_CONFIG,
"Regions already registered at postcopy-listen\n");
@@ -1760,6 +1867,9 @@ vhost_user_postcopy_end(struct virtio_net **pdev, struct VhostUserMsg *msg,
{
struct virtio_net *dev = *pdev;
+ if (validate_msg_fds(msg, 0) != 0)
+ return RTE_VHOST_MSG_RESULT_ERR;
+
dev->postcopy_listening = 0;
if (dev->postcopy_ufd >= 0) {
close(dev->postcopy_ufd);
@@ -2112,6 +2222,7 @@ vhost_user_msg_handler(int vid, int fd)
if (!handled) {
RTE_LOG(ERR, VHOST_CONFIG,
"vhost message (req: %d) was not handled.\n", request);
+ close_msg_fds(&msg);
ret = RTE_VHOST_MSG_RESULT_ERR;
}
--
2.21.0
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