[PATCH 4.9 44/68] mac80211: mesh: restrict airtime metric to peered established plinks

Greg Kroah-Hartman
2020-02-03T16:48:11Z

From: Markus Theil <markus.theil@tu-ilmenau.de>

[ Upstream commit 02a614499600af836137c3fbc4404cd96365fff2 ]

The following warning is triggered every time an unestablished mesh peer
gets dumped. Checks if a peer link is established before retrieving the
airtime link metric.

[ 9563.022567] WARNING: CPU: 0 PID: 6287 at net/mac80211/mesh_hwmp.c:345
airtime_link_metric_get+0xa2/0xb0 [mac80211]
[ 9563.022697] Hardware name: PC Engines apu2/apu2, BIOS v4.10.0.3
[ 9563.022756] RIP: 0010:airtime_link_metric_get+0xa2/0xb0 [mac80211]
[ 9563.022838] Call Trace:
[ 9563.022897] sta_set_sinfo+0x936/0xa10 [mac80211]
[ 9563.022964] ieee80211_dump_station+0x6d/0x90 [mac80211]
[ 9563.023062] nl80211_dump_station+0x154/0x2a0 [cfg80211]
[ 9563.023120] netlink_dump+0x17b/0x370
[ 9563.023130] netlink_recvmsg+0x2a4/0x480
[ 9563.023140] ____sys_recvmsg+0xa6/0x160
[ 9563.023154] ___sys_recvmsg+0x93/0xe0
[ 9563.023169] __sys_recvmsg+0x7e/0xd0
[ 9563.023210] do_syscall_64+0x4e/0x140
[ 9563.023217] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Link: https://lore.kernel.org/r/20191203180644.70653-1-markus.theil@tu-ilmenau.de
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/mesh_hwmp.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index b0acb2961e805..5f4c228b82e56 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -326,6 +326,9 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
u32 tx_time, estimated_retx;
u64 result;

+ if (sta->mesh->plink_state != NL80211_PLINK_ESTAB)
+ return MAX_METRIC;
+
/* Try to get rate based on HW/SW RC algorithm.
* Rate is returned in units of Kbps, correct this
* to comply with airtime calculation units
--
2.20.1