From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 223E2C3A5A2 for ; Tue, 3 Sep 2019 13:50:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E964F23711 for ; Tue, 3 Sep 2019 13:50:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567518626; bh=jwDqtP9jUUTCcakKBXh0Rc1jrojcO4GPILrHYrKwzRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=jgHj2+dHtAVOGzIz+LasbuH+YETj6oMId4K6GTDuo9Lz8BJbCylRR07BDDk9bj3fw 8KNRW3LUr+CvLf+uG2d6tiOJQiHMRv0qo/HsS5yf4IS9HpWjXO3JZRGPblKIPWJNEF 2aR8KffLCpY9BwjO5PwRmj/gXW4Qt0qd96WvN4iQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729005AbfICNuZ (ORCPT ); Tue, 3 Sep 2019 09:50:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:44396 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728679AbfICNuY (ORCPT ); Tue, 3 Sep 2019 09:50:24 -0400 Received: from zzz.localdomain (h184-61-154-48.mdsnwi.dsl.dynamic.tds.net [184.61.154.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8F90623697; Tue, 3 Sep 2019 13:50:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567518624; bh=jwDqtP9jUUTCcakKBXh0Rc1jrojcO4GPILrHYrKwzRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lI2oxNnhqZsLhU190DLBO0I4xF6ILS70vckJC7FnoaoxHgk+tB5TaSNNoiHJb5Q/i aEiivu6F+qB/oQjPWCrLvuXN4KQHfyoT9UwzKn99gvU6DBsKJCT/CuZSgPi3oE7z+i hZQbr+PaWD6dQh2WW+0kCu4SV8lrLYy5xvCW9wZY= Date: Tue, 3 Sep 2019 08:50:20 -0500 From: Eric Biggers To: Herbert Xu Cc: Ard Biesheuvel , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" Subject: Re: crypto: skcipher - Unmap pages after an external error Message-ID: <20190903135020.GB5144@zzz.localdomain> Mail-Followup-To: Herbert Xu , Ard Biesheuvel , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" References: <20190821143253.30209-1-ard.biesheuvel@linaro.org> <20190821143253.30209-9-ard.biesheuvel@linaro.org> <20190830080347.GA6677@gondor.apana.org.au> <20190903065438.GA9372@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190903065438.GA9372@gondor.apana.org.au> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Tue, Sep 03, 2019 at 04:54:38PM +1000, Herbert Xu wrote: > int skcipher_walk_done(struct skcipher_walk *walk, int err) > { > - unsigned int n; /* bytes processed */ > - bool more; > - > - if (unlikely(err < 0)) > - goto finish; > + unsigned int n = walk->nbytes - err; > + unsigned int nbytes; > > - n = walk->nbytes - err; > - walk->total -= n; > - more = (walk->total != 0); > + nbytes = walk->total - n; > > - if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | > - SKCIPHER_WALK_SLOW | > - SKCIPHER_WALK_COPY | > - SKCIPHER_WALK_DIFF)))) { > + if (unlikely(err < 0)) { > + nbytes = 0; > + n = 0; > + } else if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | > + SKCIPHER_WALK_SLOW | > + SKCIPHER_WALK_COPY | > + SKCIPHER_WALK_DIFF)))) { > unmap_src: > skcipher_unmap_src(walk); > } else if (walk->flags & SKCIPHER_WALK_DIFF) { > @@ -134,25 +134,34 @@ int skcipher_walk_done(struct skcipher_walk *walk, int err) > * the algorithm requires it. > */ > err = -EINVAL; > - goto finish; > - } > - skcipher_done_slow(walk, n); > - goto already_advanced; > + nbytes = 0; > + } else > + n = skcipher_done_slow(walk, n); > } > > + if (err > 0) > + err = 0; > + > + walk->total = nbytes; > + walk->nbytes = nbytes; > + > scatterwalk_advance(&walk->in, n); > scatterwalk_advance(&walk->out, n); > -already_advanced: > - scatterwalk_done(&walk->in, 0, more); > - scatterwalk_done(&walk->out, 1, more); > + scatterwalk_done(&walk->in, 0, nbytes); > + scatterwalk_done(&walk->out, 1, nbytes); > > - if (more) { > + if (nbytes) { > crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? > CRYPTO_TFM_REQ_MAY_SLEEP : 0); > return skcipher_walk_next(walk); > } > - err = 0; > -finish: > + > + return skcipher_walk_unwind(walk, err); > +} > +EXPORT_SYMBOL_GPL(skcipher_walk_done); Doesn't this re-introduce the same bug that my patch fixed -- that scatterwalk_done() could be called after 0 bytes processed, causing a crash in scatterwalk_pagedone()? - Eric