The following commit has been merged in the master branch: commit d285f52cc0f23564fd61976d43fd5b991b4828f6 Author: Sven Eckelmann sven.eckelmann@open-mesh.com Date: Tue Feb 16 10:47:07 2016 +0100

batman-adv: Fix integer overflow in batadv_iv_ogm_calc_tq

The undefined behavior sanatizer detected an signed integer overflow in a setup with near perfect link quality

UBSAN: Undefined behaviour in net/batman-adv/bat_iv_ogm.c:1246:25 signed integer overflow: 8713350 * 255 cannot be represented in type 'int'

The problems happens because the calculation of mixed unsigned and signed integers resulted in an integer multiplication.

batadv_ogm_packet::tq (u8 255) * tq_own (u8 255) * tq_asym_penalty (int 134; max 255) * tq_iface_penalty (int 255; max 255)

The tq_iface_penalty, tq_asym_penalty and inv_asym_penalty can just be changed to unsigned int because they are not expected to become negative.

Fixes: c039876892e3 ("batman-adv: add WiFi penalty") Signed-off-by: Sven Eckelmann sven.eckelmann@open-mesh.com Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli a@unstable.cc

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 1b5bbaf..ce2f203 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -1180,9 +1180,10 @@ static bool batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node, u8 total_count; u8 orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own; unsigned int neigh_rq_inv_cube, neigh_rq_max_cube; - int tq_asym_penalty, inv_asym_penalty, if_num; + int if_num; + unsigned int tq_asym_penalty, inv_asym_penalty; unsigned int combined_tq; - int tq_iface_penalty; + unsigned int tq_iface_penalty; bool ret = false;

/* find corresponding one hop neighbor */