Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753781AbbGBIfm (ORCPT ); Thu, 2 Jul 2015 04:35:42 -0400 Received: from mail-lb0-f175.google.com ([209.85.217.175]:35089 "EHLO mail-lb0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbbGBIfc (ORCPT ); Thu, 2 Jul 2015 04:35:32 -0400 MIME-Version: 1.0 In-Reply-To: <1435497454-10464-4-git-send-email-sergei@s15v.net> References: <1435497454-10464-1-git-send-email-sergei@s15v.net> <1435497454-10464-4-git-send-email-sergei@s15v.net> Date: Thu, 2 Jul 2015 10:35:30 +0200 Message-ID: Subject: Re: [PATCH RFC 3/5] kdbus: do explicit overflow check in kdbus_conn_quota_inc() From: David Herrmann To: Sergei Zviagintsev Cc: Greg Kroah-Hartman , Daniel Mack , David Herrmann , Djalal Harouni , linux-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1506 Lines: 44 Hi On Sun, Jun 28, 2015 at 3:17 PM, Sergei Zviagintsev wrote: > Replace the use of max() with explicit and obvious overflow check. > > Signed-off-by: Sergei Zviagintsev > --- > ipc/kdbus/connection.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/ipc/kdbus/connection.c b/ipc/kdbus/connection.c > index af044f93c14f..1d44e280eff0 100644 > --- a/ipc/kdbus/connection.c > +++ b/ipc/kdbus/connection.c > @@ -668,9 +668,11 @@ int kdbus_conn_quota_inc(struct kdbus_conn *c, struct kdbus_user *u, > > id = u ? u->id : KDBUS_USER_KERNEL_ID; > if (id >= c->n_quota) { > - unsigned int users; > + unsigned int users = KDBUS_ALIGN8(id) + 8; > + > + if (users < id) /* overflow */ > + users = id; > > - users = max(KDBUS_ALIGN8(id) + 8, id); To me, the max() looks fine. I mean, it should be obvious that it checks for an overflow, right? Otherwise, I'd prefer adding a comment instead of the explicit conditional. Thanks David > quota = krealloc(c->quota, users * sizeof(*quota), > GFP_KERNEL | __GFP_ZERO); > if (!quota) > -- > 1.8.3.1 > -- 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/