6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Remi Pommarel <repk@xxxxxxxxxxxx> commit f4c9c2cc827d803159730b1da813a0c595969831 upstream. 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@xxxxxxxxxxxxxxx Fixes: 4436df478860 ("batman-adv: Add flex array to struct batadv_tvlv_tt_data") Signed-off-by: Remi Pommarel <repk@xxxxxxxxxxxx> Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx> Signed-off-by: Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/batman-adv/translation-table.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- 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_v 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);