Re: [B.A.T.M.A.N.] [PATCH] batman-adv: bugfix for kernel crash in batadv_tt_local_table_free

[Antonio Quartulli <antonio@meshcoding.com>]

[-- Attachment #1: Type: text/plain, Size: 1574 bytes --]

Hi Andreas,

On 19/03/15 16:46, Andreas Pape wrote:
> This missing check lead to a kernel crash when a hard_if is removed on a 
> node forwarding
> untagged and tagged traffic (VLANID 0) to and from the mesh network.
> 

Did you actually see the crash? if so, can you please report the stacktrace?

When creating bat0 (untagged interface), a "fake" vlan object is created
with vid = BATADV_NO_FLAGS, therefore in this context the object "vlan"
should never be NULL because there is always an object to retrieve.

Cheers,

> Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
> ---
>  translation-table.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/translation-table.c b/translation-table.c
> index b20812b..4d3ab8d 100644
> --- a/translation-table.c
> +++ b/translation-table.c
> @@ -1143,8 +1143,10 @@ static void batadv_tt_local_table_free(struct 
> batadv_priv *bat_priv)
>                         /* decrease the reference held for this vlan */
>                         vlan = batadv_softif_vlan_get(bat_priv,
>  tt_common_entry->vid);
> -                       batadv_softif_vlan_free_ref(vlan);
> -                       batadv_softif_vlan_free_ref(vlan);
> +                       if (vlan) {
> +                               batadv_softif_vlan_free_ref(vlan);
> +                               batadv_softif_vlan_free_ref(vlan);
> +                       }
>  
>                         batadv_tt_local_entry_free_ref(tt_local);
>                 }
> 

-- 
Antonio Quartulli


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