diff options
| author | Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru> | 2025-02-12 08:21:25 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:39:15 +0200 |
| commit | 563917cbae6e32a33356d633bb57cf2c1d8c8ba9 (patch) | |
| tree | 73514cdc44c7671015b642e3e86ae1a54f67181f | |
| parent | 03ece0640e8f3845ae1afd4dc2691cff2e94f642 (diff) | |
wifi: mac80211: fix integer overflow in hwmp_route_info_get()
commit d00c0c4105e5ab8a6a13ed23d701cceb285761fa upstream.
Since the new_metric and last_hop_metric variables can reach
the MAX_METRIC(0xffffffff) value, an integer overflow may occur
when multiplying them by 10/9. It can lead to incorrect behavior.
Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.
Fixes: a8d418d9ac25 ("mac80211: mesh: only switch path when new metric is at least 10% better")
Cc: stable@vger.kernel.org
Signed-off-by: Ilia Gavrilov <Ilia.Gavrilov@infotecs.ru>
Link: https://patch.msgid.link/20250212082124.4078236-1-Ilia.Gavrilov@infotecs.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/mac80211/mesh_hwmp.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index b5b728a71ab5..295f98b4502e 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -360,6 +360,12 @@ u32 airtime_link_metric_get(struct ieee80211_local *local, return (u32)result; } +/* Check that the first metric is at least 10% better than the second one */ +static bool is_metric_better(u32 x, u32 y) +{ + return (x < y) && (x < (y - x / 10)); +} + /** * hwmp_route_info_get - Update routing info to originator and transmitter * @@ -450,8 +456,8 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, (mpath->sn == orig_sn && (rcu_access_pointer(mpath->next_hop) != sta ? - mult_frac(new_metric, 10, 9) : - new_metric) >= mpath->metric)) { + !is_metric_better(new_metric, mpath->metric) : + new_metric >= mpath->metric))) { process = false; fresh_info = false; } @@ -521,8 +527,8 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, if ((mpath->flags & MESH_PATH_FIXED) || ((mpath->flags & MESH_PATH_ACTIVE) && ((rcu_access_pointer(mpath->next_hop) != sta ? - mult_frac(last_hop_metric, 10, 9) : - last_hop_metric) > mpath->metric))) + !is_metric_better(last_hop_metric, mpath->metric) : + last_hop_metric > mpath->metric)))) fresh_info = false; } else { mpath = mesh_path_add(sdata, ta); |