Re: [PATCH 4/4] virtiofsd: do_read missing NULL check

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 2/4/20 12:05 PM, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Missing a NULL check if the argument fetch fails.

Surprisingly all other calls to fuse_mbuf_iter_advance() do the check.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> 
> Fixes: Coverity CID 1413119
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>   tools/virtiofsd/fuse_lowlevel.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
> index 01c418aade..704c0369b2 100644
> --- a/tools/virtiofsd/fuse_lowlevel.c
> +++ b/tools/virtiofsd/fuse_lowlevel.c
> @@ -1116,6 +1116,10 @@ static void do_read(fuse_req_t req, fuse_ino_t nodeid,
>           struct fuse_file_info fi;
>   
>           arg = fuse_mbuf_iter_advance(iter, sizeof(*arg));
> +        if (!arg) {
> +            fuse_reply_err(req, EINVAL);
> +            return;
> +        }
>   
>           memset(&fi, 0, sizeof(fi));
>           fi.fh = arg->fh;
>