linux-kernel - Re: [PATCH v3 2/2] kasan, slub: reset tag when printing address

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CA+fCnZd6d9yFZZBM-zPOC54ZiHGnCxV-XiYrCfbCTzzhRV8H1w@mail.gmail.com>
Date:   Wed, 4 Aug 2021 14:44:22 +0200
From:   Andrey Konovalov <andreyknvl@...il.com>
To:     Kuan-Ying Lee <Kuan-Ying.Lee@...iatek.com>
Cc:     Nicholas Tang <nicholas.tang@...iatek.com>,
        Andrew Yang <andrew.yang@...iatek.com>,
        Andrey Ryabinin <ryabinin.a.a@...il.com>,
        Alexander Potapenko <glider@...gle.com>,
        Marco Elver <elver@...gle.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Chinwen Chang <chinwen.chang@...iatek.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        kasan-dev <kasan-dev@...glegroups.com>,
        Linux Memory Management List <linux-mm@...ck.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>
Subject: Re: [PATCH v3 2/2] kasan, slub: reset tag when printing address

On Wed, Aug 4, 2021 at 11:10 AM Kuan-Ying Lee
<Kuan-Ying.Lee@...iatek.com> wrote:
>
> The address still includes the tags when it is printed.
> With hardware tag-based kasan enabled, we will get a
> false positive KASAN issue when we access metadata.
>
> Reset the tag before we access the metadata.
>
> Fixes: aa1ef4d7b3f6 ("kasan, mm: reset tags when accessing metadata")
> Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@...iatek.com>
> Reviewed-by: Marco Elver <elver@...gle.com>
> ---
>  mm/slub.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index b6c5205252eb..f77d8cd79ef7 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -576,8 +576,8 @@ static void print_section(char *level, char *text, u8 *addr,
>                           unsigned int length)
>  {
>         metadata_access_enable();
> -       print_hex_dump(level, kasan_reset_tag(text), DUMP_PREFIX_ADDRESS,
> -                       16, 1, addr, length, 1);
> +       print_hex_dump(level, text, DUMP_PREFIX_ADDRESS,
> +                       16, 1, kasan_reset_tag((void *)addr), length, 1);
>         metadata_access_disable();
>  }
>
> --
> 2.18.0

Reviewed-by: Andrey Konovalov <andreyknvl@...il.com>

Thanks!