cfg80211: Fix possible memory leak in function cfg80211_bss_update

stable inclusion
from stable-5.10.56
commit c8667cb406fdae6718e7dbd4d0b2c85ad1eb9d9d
bugzilla: 176004 https://gitee.com/openeuler/kernel/issues/I4DYZ4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c8667cb406fdae6718e7dbd4d0b2c85ad1eb9d9d

--------------------------------

commit f9a5c358 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: NNguyen Dinh Phi <phind.uet@gmail.com>
Link: https://lore.kernel.org/r/20210628132334.851095-1-phind.uet@gmail.comSigned-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/wireless/scan.c

@@ -1746,16 +1746,14 @@ 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;
 		}