Re: [RESEND][PATCH 1/2] keys: crypto: Replace BUG_ON() with WARN() in find_asymmetric_key()

[Greg KH <greg@kroah.com>]

On Mon, Jun 14, 2021 at 10:54:00AM +0200, Andrew Zaborowski wrote:
> Hi Greg,
> 
> On Tue, 25 May 2021 at 13:53, Greg KH <greg@kroah.com> wrote:
> > On Tue, May 25, 2021 at 01:36:27PM +0200, Andrew Zaborowski wrote:
> > > From: Jarkko Sakkinen <jarkko@kernel.org>
> > >
> > > BUG_ON() should not be used in the kernel code, unless there are
> > > exceptional reasons to do so. Replace BUG_ON() with WARN() and
> > > return.
> > >
> > > Cc: stable@vger.kernel.org
> > > Fixes: b3811d36a3e7 ("KEYS: checking the input id parameters before finding asymmetric key")
> > > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > ---
> > > No changes from original submission by Jarkko.
> > >
> > >  crypto/asymmetric_keys/asymmetric_type.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
> > > index ad8af3d70ac..a00bed3e04d 100644
> > > --- a/crypto/asymmetric_keys/asymmetric_type.c
> > > +++ b/crypto/asymmetric_keys/asymmetric_type.c
> > > @@ -54,7 +54,10 @@ struct key *find_asymmetric_key(struct key *keyring,
> > >       char *req, *p;
> > >       int len;
> > >
> > > -     BUG_ON(!id_0 && !id_1);
> > > +     if (!id_0 && !id_1) {
> > > +             WARN(1, "All ID's are NULL\n");
> >
> > You still just rebooted a machine (panic-on-warn is commonly set).
> >
> > Please just handle this properly, print an error message with dev_err()
> > or pr_err() and move on, don't crash things.
> 
> Like Eric Biggers said, a panic is probably what you want here since
> this would be a basic bug, if you even want to check this.

Ok, then keep the BUG_ON(), no change needed.

> You can't
> be looking for a key if you don't have any of the identifiers.  There
> a 4 current callers, 2 that have checks right before the call and 2
> where this could be triggered by a bug in an ASN.1 parser or
> corruption.
> 
> What's the right way to get this change merged?  There's clearly no
> need to coordinate with whoever would merge 2/2 of the series.

Why do you need to change this if BUG_ON() is the correct thing to do
here?

thanks,

greg k-h