[PATCH] net: wireless: search and hold bss in cfg80211_connect_done

[Abhishek Kumar]

If BSS instance is not provided in __cfg80211_connect_result then
a get bss is performed. This can return NULL if the BSS for the
given SSID is expired due to delayed scheduling of connect result event
in rdev->event_work. This can cause WARN_ON(!cr->bss) in
__cfg80211_connect_result to be triggered and cause cascading
failures. To mitigate this, initiate a get bss call in
cfg80211_connect_done itself and hold it to ensure that the BSS
instance does not get expired.

Signed-off-by: Abhishek Kumar <kua...@chromium.org>
---

 net/wireless/sme.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 07756ca5e3b5..52f65991accd 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -724,15 +724,8 @@ void __cfg80211_connect_result(struct net_device *dev,
        }
 #endif
 
-       if (!cr->bss && (cr->status == WLAN_STATUS_SUCCESS)) {
+       if (cr->status == WLAN_STATUS_SUCCESS)
                WARN_ON_ONCE(!wiphy_to_rdev(wdev->wiphy)->ops->connect);
-               cr->bss = cfg80211_get_bss(wdev->wiphy, NULL, cr->bssid,
-                                          wdev->ssid, wdev->ssid_len,
-                                          wdev->conn_bss_type,
-                                          IEEE80211_PRIVACY_ANY);
-               if (cr->bss)
-                       cfg80211_hold_bss(bss_from_pub(cr->bss));
-       }
 
        if (wdev->current_bss) {
                cfg80211_unhold_bss(wdev->current_bss);
@@ -882,6 +875,18 @@ void cfg80211_connect_done(struct net_device *dev,
        ev->cr.fils.update_erp_next_seq_num = 
params->fils.update_erp_next_seq_num;
        if (params->fils.update_erp_next_seq_num)
                ev->cr.fils.erp_next_seq_num = params->fils.erp_next_seq_num;
+
+       /* Acquire and hold the bss if bss is not provided in argument.
+        * This ensures that the BSS does not get expired if the schedule
+        * of the rdev->event_work gets delayed.
+        */
+       if (!params->bss && params->bssid)
+               params->bss = cfg80211_get_bss(wdev->wiphy, NULL,
+                                              params->bssid,
+                                              wdev->ssid, wdev->ssid_len,
+                                              wdev->conn_bss_type,
+                                              IEEE80211_PRIVACY_ANY);
+
        if (params->bss)
                cfg80211_hold_bss(bss_from_pub(params->bss));
        ev->cr.bss = params->bss;
-- 
2.31.0.rc2.261.g7f71774620-goog