[PATCH] wifi: mac80211: fix race condition on enabling fast-xmit

[PATCH] wifi: mac80211: fix race condition on enabling fast-xmit

[Felix Fietkau]

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>
---
 net/mac80211/sta_info.c | 1 +
 net/mac80211/tx.c       | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index bf1adcd96b41..de34aebc6064 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -909,6 +909,7 @@ 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:
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 314998fdb1a5..68a48abc7287 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3048,7 +3048,7 @@ 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