Re: [PATCH] vhost-vdpa: Fix some error handling path in vhost_vdpa_process_iotlb_msg()

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, May 22, 2022 at 03:59:01PM +0200, Christophe JAILLET wrote:
> In the error paths introduced by the commit in the Fixes tag, a mutex may
> be left locked.
> Add the correct goto instead of a direct return.
> 
> Fixes: a1468175bb17 ("vhost-vdpa: support ASID based IOTLB API")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
> WARNING: This patch only fixes the goto vs return mix-up in this function.
> However, the 2nd hunk looks really spurious to me. I think that the:
> -		return -EINVAL;
> +		r = -EINVAL;
> +		goto unlock;
> should be done only in the 'if (!iotlb)' block.
> 
> As I don't know this code, I just leave it as-is but draw your attention
> in case this is another bug lurking.
> ---
>  drivers/vhost/vdpa.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 1f1d1c425573..3e86080041fc 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -1000,7 +1000,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
>  		if (!as) {
>  			dev_err(&v->dev, "can't find and alloc asid %d\n",
>  				asid);
> -			return -EINVAL;
> +			r = -EINVAL;
> +			goto unlock;
>  		}
>  		iotlb = &as->iotlb;
>  	} else
> @@ -1013,7 +1014,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
>  		}
>  		if (!iotlb)
>  			dev_err(&v->dev, "no iotlb for asid %d\n", asid);
> -		return -EINVAL;
> +		r = -EINVAL;
> +		goto unlock;
>  	}
>  
>  	switch (msg->type) {
> -- 
> 2.34.1