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From: Kees Cook <keescook@chromium.org>
To: Christian Brauner <brauner@kernel.org>
Cc: Jann Horn <jannh@google.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org,
	kernel-hardening@lists.openwall.com
Subject: Re: [PATCH] fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detected
Date: Fri, 27 Jan 2023 10:38:19 -0800	[thread overview]
Message-ID: <202301271038.1E64668B@keescook> (raw)
In-Reply-To: <20230127105815.adgqe2opfzruxk7e@wittgenstein>

On Fri, Jan 27, 2023 at 11:58:15AM +0100, Christian Brauner wrote:
> On Thu, Jan 26, 2023 at 08:35:49AM -0800, Kees Cook wrote:
> > On Mon, Jan 16, 2023 at 08:14:25PM +0100, Jann Horn wrote:
> > > Currently, filp_close() and generic_shutdown_super() use printk() to log
> > > messages when bugs are detected. This is problematic because infrastructure
> > > like syzkaller has no idea that this message indicates a bug.
> > > In addition, some people explicitly want their kernels to BUG() when kernel
> > > data corruption has been detected (CONFIG_BUG_ON_DATA_CORRUPTION).
> > > And finally, when generic_shutdown_super() detects remaining inodes on a
> > > system without CONFIG_BUG_ON_DATA_CORRUPTION, it would be nice if later
> > > accesses to a busy inode would at least crash somewhat cleanly rather than
> > > walking through freed memory.
> > > 
> > > To address all three, use CHECK_DATA_CORRUPTION() when kernel bugs are
> > > detected.
> > 
> > Seems reasonable to me. I'll carry this unless someone else speaks up.
> 
> I've already picked this into a branch with other fs changes for coming cycle.

Okay, great! I'll drop it from my tree.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

      reply	other threads:[~2023-01-27 18:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-16 19:14 [PATCH] fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detected Jann Horn
2023-01-24 10:12 ` Christian Brauner
2023-01-26 16:35 ` Kees Cook
2023-01-27 10:58   ` Christian Brauner
2023-01-27 18:38     ` Kees Cook [this message]

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