linux-kernel - Re: [PATCH v1 4/4] xen/netback: Fix grant copy across page boundary with KASAN

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

Message-ID: <CACCGGhCGcdEq7CC3J0201ETvAd+PZ2fTDNUS3mo599Tuf-61yA@mail.gmail.com>
Date:   Thu, 9 Jan 2020 13:36:22 +0000
From:   Paul Durrant <pdurrant@...il.com>
To:     Sergey Dyasli <sergey.dyasli@...rix.com>
Cc:     xen-devel@...ts.xen.org, kasan-dev@...glegroups.com,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Alexander Potapenko <glider@...gle.com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        George Dunlap <george.dunlap@...rix.com>,
        Ross Lagerwall <ross.lagerwall@...rix.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Wei Liu <wei.liu@...nel.org>
Subject: Re: [PATCH v1 4/4] xen/netback: Fix grant copy across page boundary
 with KASAN

On Wed, 8 Jan 2020 at 15:21, Sergey Dyasli <sergey.dyasli@...rix.com> wrote:
>
> From: Ross Lagerwall <ross.lagerwall@...rix.com>
>
> When KASAN (or SLUB_DEBUG) is turned on, the normal expectation that
> allocations are aligned to the next power of 2 of the size does not
> hold. Therefore, handle grant copies that cross page boundaries.
>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@...rix.com>
> Signed-off-by: Sergey Dyasli <sergey.dyasli@...rix.com>
> ---
> RFC --> v1:
> - Added BUILD_BUG_ON to the netback patch
> - xenvif_idx_release() now located outside the loop
>
> CC: Wei Liu <wei.liu@...nel.org>
> CC: Paul Durrant <paul@....org>
[snip]
>
> +static void __init __maybe_unused build_assertions(void)
> +{
> +       BUILD_BUG_ON(sizeof(struct xenvif_tx_cb) > 48);

FIELD_SIZEOF(struct sk_buff, cb) rather than a magic '48' I think.

  Paul

> +}
> +
>  MODULE_LICENSE("Dual BSD/GPL");
>  MODULE_ALIAS("xen-backend:vif");
> --
> 2.17.1
>