From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id EA0BE6B0266 for ; Fri, 1 Jul 2016 03:53:35 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id g62so221338207pfb.3 for ; Fri, 01 Jul 2016 00:53:35 -0700 (PDT) Received: from mail-pa0-x242.google.com (mail-pa0-x242.google.com. [2607:f8b0:400e:c03::242]) by mx.google.com with ESMTPS id yk3si2971213pac.233.2016.07.01.00.53.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Jul 2016 00:53:35 -0700 (PDT) Received: by mail-pa0-x242.google.com with SMTP id ts6so9203236pac.0 for ; Fri, 01 Jul 2016 00:53:35 -0700 (PDT) From: js1304@gmail.com Subject: [PATCH] kasan/quarantine: fix NULL pointer dereference bug Date: Fri, 1 Jul 2016 16:53:48 +0900 Message-Id: <1467359628-8493-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim From: Joonsoo Kim If we move an item on qlist's tail, we need to update qlist's tail properly. curr->next can be NULL since it is singly linked list so it is invalid for tail. curr is scheduled to be moved so using prev would be correct. Unfortunately, I got this bug sometime ago and lose oops message. But, the bug looks trivial and no need to attach oops. Signed-off-by: Joonsoo Kim --- mm/kasan/quarantine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 4973505..9a132fd 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -255,7 +255,7 @@ static void qlist_move_cache(struct qlist_head *from, } else prev->next = curr->next; if (unlikely(from->tail == qlink)) - from->tail = curr->next; + from->tail = prev; from->bytes -= cache->size; qlist_put(to, qlink, cache->size); } else { -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org