Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752526AbaKQPbB (ORCPT ); Mon, 17 Nov 2014 10:31:01 -0500 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:42195 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752358AbaKQPa7 (ORCPT ); Mon, 17 Nov 2014 10:30:59 -0500 X-IronPort-AV: E=Sophos;i="5.07,403,1413237600"; d="scan'208";a="107663365" Date: Mon, 17 Nov 2014 16:30:11 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Konstantin Khlebnikov cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Biederman , Michal Marek , Herbert Xu , Gilles Muller , Nicolas Palix , linux-crypto@vger.kernel.org, "David S. Miller" Subject: Re: [PATCH 1/2] scripts/coccinelle: catch freeing cryptographic structures via kfree In-Reply-To: <20141117151420.10739.16342.stgit@buzz> Message-ID: References: <20141117151420.10739.16342.stgit@buzz> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 17 Nov 2014, Konstantin Khlebnikov wrote: > Structures allocated by crypto_alloc_* must be freed using crypto_free_*. > > Signed-off-by: Konstantin Khlebnikov > --- > scripts/coccinelle/free/crypto_free.cocci | 45 +++++++++++++++++++++++++++++ > 1 file changed, 45 insertions(+) > create mode 100644 scripts/coccinelle/free/crypto_free.cocci > > diff --git a/scripts/coccinelle/free/crypto_free.cocci b/scripts/coccinelle/free/crypto_free.cocci > new file mode 100644 > index 0000000..0799b70 > --- /dev/null > +++ b/scripts/coccinelle/free/crypto_free.cocci > @@ -0,0 +1,45 @@ > +/// > +/// Structures allocated by crypto_alloc_* must be freed using crypto_free_*. > +/// This finds freeing them by kfree. > +/// > +// Confidence: Moderate > +// Copyright: (C) 2014 Konstantin Khlebnikov, GPLv2. > +// Comments: There are false positives in crypto/ where they are actually freed. > +// Keywords: crypto, kfree > +// Options: --no-includes --include-headers > + > +virtual org > +virtual report > +virtual context > + > +@r depends on context || org || report@ > +expression x; > +identifier crypto_alloc =~ "^crypto_alloc_"; > +@@ > + > +( > + x = crypto_alloc(...) > +) You can drop the outer parentheses, in this case and in the kfree case. Are there many of these crypto_alloc_ functions? It would be nicer to avoid the regular expression. For one thing, you don't have much control over what it matches, and for another thing Coccinelle will not be able to optimize the selection of files. With the regular expression it will have to parse every file and analyze every function, which will be slow. julia > + > +@pb@ > +expression r.x; > +position p; > +@@ > + > +( > +* kfree@p(x) > +) > + > +@script:python depends on org@ > +p << pb.p; > +@@ > + > +msg="WARNING: invalid free of crypto_alloc_* allocated data" > +coccilib.org.print_todo(p[0], msg) > + > +@script:python depends on report@ > +p << pb.p; > +@@ > + > +msg="WARNING: invalid free of crypto_alloc_* allocated data" > +coccilib.report.print_report(p[0], msg) > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/