[PATCH] batman-adv: fix potential NULL pointer dereferencing

[PATCH] batman-adv: fix potential NULL pointer dereferencing

[Mario Pirker]

>From b451e7317148e18bf6c5c8fd747d79ab34260354 Mon Sep 17 00:00:00 2001
From: Mario Pirker <mario.pirker@kellogg.ox.ac.uk>
Date: Tue, 16 Sep 2014 17:55:13 +0200
Subject: [PATCH] batman-adv: fix potential NULL pointer dereferencing

The call batadv_gw_node_get may return NULL. The return value has to
be sanity checked before the pointer is dereferenced.

Signed-off-by: Mario Pirker <mariopirker@hotmail.com>
---
 net/batman-adv/gateway_client.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 90cff58..7ee0913 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -810,6 +810,11 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
                goto out;
 
        gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
+
+       /* gw_node can be NULL. We need to check before dereferencing */
+       if (gw_node == NULL)
+               goto out;
+
        if (!gw_node->bandwidth_down == 0)
                goto out;
 
-- 
1.8.1.4 		 	   		  

Re: [PATCH] batman-adv: fix potential NULL pointer dereferencing

[Antonio Quartulli]

[-- Attachment #1: Type: text/plain, Size: 1486 bytes --]



On 22/09/14 11:11, Mario Pirker wrote:
> From b451e7317148e18bf6c5c8fd747d79ab34260354 Mon Sep 17 00:00:00 2001
> From: Mario Pirker <mario.pirker@kellogg.ox.ac.uk>
> Date: Tue, 16 Sep 2014 17:55:13 +0200
> Subject: [PATCH] batman-adv: fix potential NULL pointer dereferencing
> 
> The call batadv_gw_node_get may return NULL. The return value has to
> be sanity checked before the pointer is dereferenced.
> 
> Signed-off-by: Mario Pirker <mariopirker@hotmail.com>
> ---

We already have a patch queued to fix this issue
(http://permalink.gmane.org/gmane.org.freifunk.batman/12357).

Actually it is not about a missing check but it is more about a typo in
the check right below the one you added.

Cheers,

>  net/batman-adv/gateway_client.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
> index 90cff58..7ee0913 100644
> --- a/net/batman-adv/gateway_client.c
> +++ b/net/batman-adv/gateway_client.c
> @@ -810,6 +810,11 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
>                 goto out;
>  
>         gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
> +
> +       /* gw_node can be NULL. We need to check before dereferencing */
> +       if (gw_node == NULL)
> +               goto out;
> +
>         if (!gw_node->bandwidth_down == 0)
>                 goto out;
>  
> -- 
> 1.8.1.4 		 	   		  
> 

-- 
Antonio Quartulli


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]