Re: [PATCH] vhost: return EINVAL if iovecs size does not match the message size
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2018-12-13 19:55:17
On Thu, Dec 13, 2018 at 05:53:50PM +0300, Pavel Tikhomirov wrote:
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>Thanks for the patch!
quoted hunk
--- drivers/vhost/vhost.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 3a5f81a66d34..03014224ef13 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c@@ -1024,8 +1024,10 @@ 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:
should this be EFAULT rather?
quoted hunk
@@ -1044,8 +1046,10 @@ 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;
This too?
-- 2.17.1