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 71a8e6980e2fc80ae2d639a603517d8c23081ee0..901a8742a28dce33e6a352ee9144c7144b9899f2 100644 (file)
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -949,16 +949,14 @@ 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;
                }