cfg80211: Fix possible memory leak in function cfg80211_bss_update

commit f9a5c358c8d26fed0cc45f2afc64633d4ba21dff upstream.

When we exceed the limit of BSS entries, this function will free the
new entry, however, at this time, it is the last door to access the
inputed ies, so these ies will be unreferenced objects and cause memory
leak.
Therefore we should free its ies before deallocating the new entry, beside
of dropping it from hidden_list.

Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Link: https://lore.kernel.org/r/20210628132334.851095-1-phind.uet@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 67b2747ad9ef890fc05425c248c242dc4b5cb417..d871349036a5cdc900eaf2eca6839f49fc72e6ca 100644 (file)
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1029,16 +1029,14 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
                         * be grouped with this beacon for updates ...
                         */
                        if (!cfg80211_combine_bsses(rdev, new)) {
-                               kfree(new);
+                               bss_ref_put(rdev, new);
                                goto drop;
                        }
                }
 
                if (rdev->bss_entries >= bss_entries_limit &&
                    !cfg80211_bss_expire_oldest(rdev)) {
-                       if (!list_empty(&new->hidden_list))
-                               list_del(&new->hidden_list);
-                       kfree(new);
+                       bss_ref_put(rdev, new);
                        goto drop;
                }