linux-kernel - Re: [PATCH] hte: Annotate struct hte_device with __counted

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: <CAFhGd8oz9zTVacJMEWv4-hpNeXbPLYQ6fnb2z_2Y++rWyVSUow@mail.gmail.com>
Date:   Thu, 28 Sep 2023 13:42:39 +0900
From:   Justin Stitt <justinstitt@...gle.com>
To:     Kees Cook <keescook@...omium.org>
Cc:     Dipen Patel <dipenp@...dia.com>, timestamp@...ts.linux.dev,
        Nathan Chancellor <nathan@...nel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Tom Rix <trix@...hat.com>, linux-kernel@...r.kernel.org,
        llvm@...ts.linux.dev, linux-hardening@...r.kernel.org
Subject: Re: [PATCH] hte: Annotate struct hte_device with __counted_by

On Sat, Sep 23, 2023 at 2:54 AM Kees Cook <keescook@...omium.org> wrote:
>
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct hte_device.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Dipen Patel <dipenp@...dia.com>
> Cc: timestamp@...ts.linux.dev
> Signed-off-by: Kees Cook <keescook@...omium.org>

Yep, this flexible array member is counted by @nlines which
is evident throughout hte.c:

        gdev = kzalloc(struct_size(gdev, ei, chip->nlines), GFP_KERNEL);
        ...
        gdev->nlines = chip->nlines;
        ...
        for (i = 0; i < chip->nlines; i++) {
          gdev->ei[i].gdev = gdev;
        ...


Reviewed-by: Justin Stitt <justinstitt@...gle.com>

> ---
>  drivers/hte/hte.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hte/hte.c b/drivers/hte/hte.c
> index 598a716b7364..1fd8d2d4528b 100644
> --- a/drivers/hte/hte.c
> +++ b/drivers/hte/hte.c
> @@ -88,7 +88,7 @@ struct hte_device {
>         struct list_head list;
>         struct hte_chip *chip;
>         struct module *owner;
> -       struct hte_ts_info ei[];
> +       struct hte_ts_info ei[] __counted_by(nlines);
>  };
>
>  #ifdef CONFIG_DEBUG_FS
> --
> 2.34.1
>
>