Re: [PATCH] fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detected

From: Christian Brauner
Date: Fri Jan 27 2023 - 05:58:39 EST


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.

Al, please tell me in case you end up picking this up and I'll drop it ofc.

Christian