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authorSven Eckelmann <sven.eckelmann@open-mesh.com>2016-02-16 10:47:07 +0100
committerAntonio Quartulli <a@unstable.cc>2016-05-18 11:49:42 +0800
commitd285f52cc0f23564fd61976d43fd5b991b4828f6 (patch)
treecb94178c532da21ddc3a53a82665bcaef9e1645a /net/batman-adv/bat_iv_ogm.c
parent1653f61d656516aae7130db19561258a847d1e94 (diff)
downloadlinux-d285f52cc0f23564fd61976d43fd5b991b4828f6.tar.bz2
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>
Diffstat (limited to 'net/batman-adv/bat_iv_ogm.c')
-rw-r--r--net/batman-adv/bat_iv_ogm.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 1b5bbafc0fa3..ce2f203048d3 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 */