[PATCH 5.4 16/84] wifi: mac80211: fix race condition on enabling fast-xmit

Greg Kroah-Hartman
2024-02-27T14:23:30Z

From: Felix Fietkau <nbd@nbd.name>

[ Upstream commit bcbc84af1183c8cf3d1ca9b78540c2185cd85e7f ]

fast-xmit must only be enabled after the sta has been uploaded to the driver,
otherwise it could end up passing the not-yet-uploaded sta via drv_tx calls
to the driver, leading to potential crashes because of uninitialized drv_priv
data.
Add a missing sta->uploaded check and re-check fast xmit after inserting a sta.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://msgid.link/20240104181059.84032-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/sta_info.c | 2 ++
net/mac80211/tx.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 0f97c6fcec174..e330036e02eac 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -683,6 +683,8 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
if (ieee80211_vif_is_mesh(&sdata->vif))
mesh_accept_plinks_update(sdata);

+ ieee80211_check_fast_xmit(sta);
+
return 0;
out_remove:
sta_info_hash_del(local, sta);
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 8bd01dfa75cb1..5fd9a6f752a1d 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2919,7 +2919,7 @@ void ieee80211_check_fast_xmit(struct sta_info *sta)
sdata->vif.type == NL80211_IFTYPE_STATION)
goto out;

- if (!test_sta_flag(sta, WLAN_STA_AUTHORIZED))
+ if (!test_sta_flag(sta, WLAN_STA_AUTHORIZED) || !sta->uploaded)
goto out;

if (test_sta_flag(sta, WLAN_STA_PS_STA) ||
--
2.43.0