vhost: return EINVAL if iovecs size does not match the message size

We've failed to copy and process vhost_iotlb_msg so let userspace at
least know about it. For instance before these patch the code below runs
without any error:

int main()
{
  struct vhost_msg msg;
  struct iovec iov;
  int fd;

  fd = open("/dev/vhost-net", O_RDWR);
  if (fd == -1) {
    perror("open");
    return 1;
  }

  iov.iov_base = &msg;
  iov.iov_len = sizeof(msg)-4;

  if (writev(fd, &iov,1) == -1) {
    perror("writev");
    return 1;
  }

  return 0;
}

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Pavel Tikhomirov 2018-12-13 17:53:50 +03:00 committed by Michael S. Tsirkin
parent bf4dc0b2be
commit 74ad741948
1 changed files with 6 additions and 2 deletions

View File

@ -1034,8 +1034,10 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
int type, ret;
ret = copy_from_iter(&type, sizeof(type), from);
if (ret != sizeof(type))
if (ret != sizeof(type)) {
ret = -EINVAL;
goto done;
}
switch (type) {
case VHOST_IOTLB_MSG:
@ -1054,8 +1056,10 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
iov_iter_advance(from, offset);
ret = copy_from_iter(&msg, sizeof(msg), from);
if (ret != sizeof(msg))
if (ret != sizeof(msg)) {
ret = -EINVAL;
goto done;
}
if (vhost_process_iotlb_msg(dev, &msg)) {
ret = -EFAULT;
goto done;