Re: [PATCH v3 5/5] vfio-user: recycle msg on failure

[Mark Cave-Ayland <mark.caveayland@nutanix.com>]

On 01/12/2025 09:56, John Levon wrote:

> If we fail to read an incoming request, recycle the message.
> 
> Resolves: Coverity CID 1611807
> Resolves: Coverity CID 1611808
> Signed-off-by: John Levon <john.levon@nutanix.com>
> ---
>   hw/vfio-user/proxy.c | 21 ++++++++++++++++-----
>   1 file changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/vfio-user/proxy.c b/hw/vfio-user/proxy.c
> index d1d63816b3..d06978a74f 100644
> --- a/hw/vfio-user/proxy.c
> +++ b/hw/vfio-user/proxy.c
> @@ -412,11 +412,22 @@ err:
>       for (i = 0; i < numfds; i++) {
>           close(fdp[i]);
>       }
> -    if (isreply && msg != NULL) {
> -        /* force an error to keep sending thread from hanging */
> -        vfio_user_set_error(msg->hdr, EINVAL);
> -        msg->complete = true;
> -        qemu_cond_signal(&msg->cv);
> +    if (msg != NULL) {
> +        if (msg->type == VFIO_MSG_REQ) {
> +            /*
> +             * Clean up the request message on failure. Change type back to
> +             * NOWAIT to free.
> +             */
> +            msg->type = VFIO_MSG_NOWAIT;
> +            vfio_user_recycle(proxy, msg);
> +        } else {
> +            /*
> +             * Report an error back to the sender. Sender will recycle msg.
> +             */
> +            vfio_user_set_error(msg->hdr, EINVAL);
> +            msg->complete = true;
> +            qemu_cond_signal(&msg->cv);
> +        }
>       }
>       return -1;
>   }

Reviewed-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>


ATB,

Mark.