linux-kernel - Re: [PATCH] drm/panfrost: Avoid user size passed to kvmalloc()

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: <20211217091046.GG1978@kadam>
Date:   Fri, 17 Dec 2021 12:10:46 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Steven Price <steven.price@....com>
Cc:     Rob Herring <robh@...nel.org>, Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...ux.ie>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>,
        Alyssa Rosenzweig <alyssa.rosenzweig@...labora.com>,
        Boris Brezillon <boris.brezillon@...labora.com>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/panfrost: Avoid user size passed to kvmalloc()

On Fri, Dec 17, 2021 at 08:55:50AM +0000, Steven Price wrote:
> However this one is harder to fix without setting an arbitrary cap on
> the number of BOs during a sumbit. I'm not sure how other drivers handle
> this - the ones I've looked at so far all have the same issue. There's
> obviously the list that Dan already sent, but e.g. msm has the same bug
> in msm_gem_submit.c:submit_create() with an amusing bug where the check
> for (sz > SIZE_MAX) will never hit, although the call is to kzalloc() so
> large allocations are going to fail anyway.

sz is u64 and SIZE_MAX is ULONG_MAX so the (sz > SIZE_MAX) condition
does work to prevent an integer overflow on 32bit systems.  But it's not
beautiful.

regards,
dan carpenter