Re: [PATCH 2/2] crypto: chcr - Fix error checking

[Christophe JAILLET]

Le 13/04/2017 à 16:04, Dan Carpenter a écrit :
> On Thu, Apr 13, 2017 at 02:14:30PM +0200, Christophe JAILLET wrote:
> > If 'chcr_alloc_shash()' a few lines above fails, 'base_hash' can be an
> > error pointer when we 'goto out'.
> > So checking for NULL here is not enough because it is likely that
> > 'chcr_free_shash' will crash if we pass an error pointer.
> >
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > ---
> > Another solution, amybe safer, would be to instrument 'chcr_free_shash' or
> > 'crypto_free_shash' to accept an error pointer and return immediatelly in
> > such a case.
> > ---
> >   drivers/crypto/chelsio/chcr_algo.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/crypto/chelsio/chcr_algo.c b/drivers/crypto/chelsio/chcr_algo.c
> > index f19590ac8775..41750b97f43c 100644
> > --- a/drivers/crypto/chelsio/chcr_algo.c
> > +++ b/drivers/crypto/chelsio/chcr_algo.c
> > @@ -2351,7 +2351,7 @@ static int chcr_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
> >   	}
> >   out:
> >   	aeadctx->enckey_len = 0;
> > -	if (base_hash)
> > +	if (!IS_ERR_OR_NULL(base_hash))
> >   		chcr_free_shash(base_hash);
> Ah...  Ok.  Fine, but redo the first patch anyway because it shouldn't
> ever be NULL.
>
> regards,
> dan carpenter
Hi Dan,

I will update the first patch as you proposed in order to:
   - teach 'chcr_alloc_shash' not to return NULL
   - initialize 'base_hash' with ERR_PTR(-EINVAL)
   - update the above test to !IS_ERR.
The 2 patches will be merged in only 1.

Thanks for your suggestions.

Best regards,
CJ