The following commit has been merged in the merge/master branch: commit 789b846af6a9471982b181687a1cba8dc996b269 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: 46e44fdb96ef ("batman-adv: add WiFi penalty") Signed-off-by: Sven Eckelmann sven.eckelmann@open-mesh.com Signed-off-by: Marek Lindner mareklindner@neomailbox.ch

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index ea553fe..da0ad2b 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -1137,9 +1137,10 @@ static int 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, ret = 0; + int if_num, ret = 0; + unsigned int tq_asym_penalty, inv_asym_penalty; unsigned int combined_tq; - int tq_iface_penalty; + unsigned int tq_iface_penalty;

/* find corresponding one hop neighbor */ rcu_read_lock();