From: Remi Pommarel repk@triplefau.lt

Since commit 4436df478860 ("batman-adv: Add flex array to struct batadv_tvlv_tt_data"), the introduction of batadv_tvlv_tt_data's flex array member in batadv_tt_tvlv_ogm_handler_v1() put tt_changes at invalid offset. Those TT changes are supposed to be filled from the end of batadv_tvlv_tt_data structure (including vlan_data flexible array), but only the flex array size is taken into account missing completely the size of the fixed part of the structure itself.

Fix the tt_change offset computation by using struct_size() instead of flex_array_size() so both flex array member and its container structure sizes are taken into account.

Cc: stable@vger.kernel.org Fixes: 4436df478860 ("batman-adv: Add flex array to struct batadv_tvlv_tt_data") Signed-off-by: Remi Pommarel repk@triplefau.lt Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/translation-table.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 760d51fdbdf6..7d5de4cbb814 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -3959,23 +3959,21 @@ static void batadv_tt_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, struct batadv_tvlv_tt_change *tt_change; struct batadv_tvlv_tt_data *tt_data; u16 num_entries, num_vlan; - size_t flex_size; + size_t tt_data_sz;

if (tvlv_value_len < sizeof(*tt_data)) return;

tt_data = tvlv_value; - tvlv_value_len -= sizeof(*tt_data); - num_vlan = ntohs(tt_data->num_vlan);

- flex_size = flex_array_size(tt_data, vlan_data, num_vlan); - if (tvlv_value_len < flex_size) + tt_data_sz = struct_size(tt_data, vlan_data, num_vlan); + if (tvlv_value_len < tt_data_sz) return;

tt_change = (struct batadv_tvlv_tt_change *)((void *)tt_data - + flex_size); - tvlv_value_len -= flex_size; + + tt_data_sz); + tvlv_value_len -= tt_data_sz;

num_entries = batadv_tt_entries(tvlv_value_len);