From: Kees Cook <kees@kernel.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: "Christian Brauner" <brauner@kernel.org>,
syzbot+a9391462075ffb9f77c6@syzkaller.appspotmail.com,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Christian König" <christian.koenig@amd.com>,
linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: Re: [PATCH] dma-buf: use SB_I_NOEXEC and SB_I_NODEV
Date: Fri, 10 Oct 2025 15:57:26 -0700 [thread overview]
Message-ID: <202510101556.5C71F86@keescook> (raw)
In-Reply-To: <aOYBpY7jPx622xcz@infradead.org>
On Tue, Oct 07, 2025 at 11:16:05PM -0700, Christoph Hellwig wrote:
> On Tue, Oct 07, 2025 at 11:10:32PM -0700, Kees Cook wrote:
> > The dma-buf pseudo-filesystem should never have executable mappings nor
> > device nodes. Set SB_I_NOEXEC and SB_I_NODEV on the superblock to enforce
> > this at the filesystem level, similar to secretmem, commit 98f99394a104
> > ("secretmem: use SB_I_NOEXEC").
> >
> > Fix the syzbot-reported warning from the exec code to enforce this
> > requirement:
>
> Can you please just enforce this in init_pseudo? If a file system
> really wants to support devices or executable it can clear them,
> but a quick grep suggests that none of them should.
I that that's a fine idea, but I defer to Christian -- I think the WARN
was put in place to avoid doing that...
--
Kees Cook
prev parent reply other threads:[~2025-10-10 22:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-08 6:10 [PATCH] dma-buf: use SB_I_NOEXEC and SB_I_NODEV Kees Cook
[not found] ` <aOYBpY7jPx622xcz@infradead.org>
2025-10-10 22:57 ` Kees Cook [this message]
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