[ovs-dev] [PATCH] bridge: Forbid '/' in bridge names to prevent arbitrary directory access.

[Justin Pettit]

What about '\' for when we're ported to Hyper-V?  j/k

Looks good.

--Justin


On Oct 14, 2011, at 10:20 AM, Ben Pfaff wrote:

> ---
> vswitchd/bridge.c |   11 +++++++++--
> 1 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
> index b5071e2..f9cf9e7 100644
> --- a/vswitchd/bridge.c
> +++ b/vswitchd/bridge.c
> @@ -739,9 +739,16 @@ add_del_bridges(const struct ovsrec_open_vswitch *cfg)
>     /* Collect new bridges' names and types. */
>     shash_init(&new_br);
>     for (i = 0; i < cfg->n_bridges; i++) {
> +        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
>         const struct ovsrec_bridge *br_cfg = cfg->bridges[i];
> -        if (!shash_add_once(&new_br, br_cfg->name, br_cfg)) {
> -            VLOG_WARN("bridge %s specified twice", br_cfg->name);
> +
> +        if (strchr(br_cfg->name, '/')) {
> +            /* Prevent remote ovsdb-server users from accessing arbitrary
> +             * directories, e.g. consider a bridge named "../../../etc/". */
> +            VLOG_WARN_RL(&rl, "ignoring bridge with invalid name \"%s\"",
> +                         br_cfg->name);
> +        } else if (!shash_add_once(&new_br, br_cfg->name, br_cfg)) {
> +            VLOG_WARN_RL(&rl, "bridge %s specified twice", br_cfg->name);
>         }
>     }
> 
> -- 
> 1.7.4.4
> 
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