From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f181.google.com (mail-wi0-f181.google.com [209.85.212.181]) by kanga.kvack.org (Postfix) with ESMTP id 866866B0038 for ; Wed, 9 Sep 2015 05:40:15 -0400 (EDT) Received: by wicge5 with SMTP id ge5so147531304wic.0 for ; Wed, 09 Sep 2015 02:40:15 -0700 (PDT) Received: from mail-wi0-x236.google.com (mail-wi0-x236.google.com. [2a00:1450:400c:c05::236]) by mx.google.com with ESMTPS id wb10si3550165wic.81.2015.09.09.02.40.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Sep 2015 02:40:14 -0700 (PDT) Received: by wicfx3 with SMTP id fx3so14644623wic.0 for ; Wed, 09 Sep 2015 02:40:14 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1441771180-206648-3-git-send-email-long.wanglong@huawei.com> References: <1441771180-206648-1-git-send-email-long.wanglong@huawei.com> <1441771180-206648-3-git-send-email-long.wanglong@huawei.com> Date: Wed, 9 Sep 2015 12:40:13 +0300 Message-ID: Subject: Re: [PATCH 2/2] kasan: Fix a type conversion error From: Andrey Ryabinin Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Wang Long Cc: Andrey Konovalov , Andrew Morton , Rusty Russell , "linux-mm@kvack.org" , LKML , wanglong@laoqinren.net, peifeiyue@huawei.com, morgan.wang@huawei.com 2015-09-09 6:59 GMT+03:00 Wang Long : > The current KASAN code can find the following out-of-bounds > bugs: > char *ptr; > ptr = kmalloc(8, GFP_KERNEL); > memset(ptr+7, 0, 2); > > the cause of the problem is the type conversion error in > *memory_is_poisoned_n* function. So this patch fix that. > > Signed-off-by: Wang Long > --- > mm/kasan/kasan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c > index 7b28e9c..5d65d06 100644 > --- a/mm/kasan/kasan.c > +++ b/mm/kasan/kasan.c > @@ -204,7 +204,7 @@ static __always_inline bool memory_is_poisoned_n(unsigned long addr, > s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); > > if (unlikely(ret != (unsigned long)last_shadow || > - ((last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) > + ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) Is there any problem if we just define last_byte as 'long' instead of 'unsigned long' ? > return true; > } > return false; > -- > 1.8.3.4 > -- 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