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From:   Qian Cai <cai@lca.pw>
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Subject: Re: [PATCH] kasan: fix the missing underflow in memmove and memcpy with CONFIG_KASAN_GENERIC=y
Date:   Tue, 8 Oct 2019 07:42:47 -0400
Message-Id: <D2B6D82F-AE5F-4A45-AC0C-BE5DA601FDC3@lca.pw>
References: <1570532528.4686.102.camel@mtksdccf07>
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Linux-MM <linux-mm@kvack.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-mediatek@lists.infradead.org,
        wsd_upstream <wsd_upstream@mediatek.com>
In-Reply-To: <1570532528.4686.102.camel@mtksdccf07>
To:     Walter Wu <walter-zh.wu@mediatek.com>
Sender: linux-kernel-owner@vger.kernel.org
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> On Oct 8, 2019, at 7:02 AM, Walter Wu <walter-zh.wu@mediatek.com> wrote:
>=20
> I don't know very well in UBSAN, but I try to build ubsan kernel and
> test a negative number in memset and kmalloc_memmove_invalid_size(), it
> look like no check.

It sounds like more important to figure out why the UBSAN is not working in t=
his case rather than duplicating functionality elsewhere.=