Neil Brown wrote:
> Currently if probe port is asked to probe for a specific version, and
> that version is not supported, it will probe other versions too.
> This means that if mountd is run with "--no-nfs-version 3",
> It will first probe for NFS version 3, which will succeed (assuming the
> kernel supported NFSv3), then it will check the matching mountd version (3)
> and probe_port on discovering that isn't supported will try other versions,
> find "1" is supported will succeed.
> 
> This leaves us using mount version 1 for an NFSv3 mount, which doesn't work
> and leads to a SIGSEGV
> 
> There is no case where trying other versions is needed the request one is
> not supported, so simply remove that code.

I agree with that understanding:  if the caller is asking for a specific 
version of the protocol in question, we aren't looking for a wildcard.

Time to add another case to our list of regression tests.

I wonder if the same misbehavior occurs when probing for transport 
protocols?

> Signed-off-by: Neil Brown <neilb@suse.de>
> ---
>  utils/mount/network.c |    4 ----
>  1 files changed, 0 insertions(+), 4 deletions(-)
> 
> diff --git a/utils/mount/network.c b/utils/mount/network.c
> index 63d5f5a..2b09457 100644
> --- a/utils/mount/network.c
> +++ b/utils/mount/network.c
> @@ -417,10 +417,6 @@ static int probe_port(clnt_addr_t *server, const unsigned long *versions,
>  				continue;
>  			p_prot = protos;
>  		}
> -		if (vers == pmap->pm_vers) {
> -			p_vers = versions;
> -			vers = 0;
> -		}
>  		if (vers || !*++p_vers)
>  			break;
>  	}