Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751507AbdFFUgn (ORCPT ); Tue, 6 Jun 2017 16:36:43 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:39746 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426AbdFFUgm (ORCPT ); Tue, 6 Jun 2017 16:36:42 -0400 Date: Tue, 06 Jun 2017 16:36:39 -0400 (EDT) Message-Id: <20170606.163639.1246601020260541080.davem@davemloft.net> To: glider@google.com Cc: dvyukov@google.com, kcc@google.com, edumazet@google.com, stephen@networkplumber.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH v4] net: don't call strlen on non-terminated string in dev_set_alias() From: David Miller In-Reply-To: <20170606135654.111884-1-glider@google.com> References: <20170606135654.111884-1-glider@google.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 06 Jun 2017 12:55:02 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 594 Lines: 17 From: Alexander Potapenko Date: Tue, 6 Jun 2017 15:56:54 +0200 > KMSAN reported a use of uninitialized memory in dev_set_alias(), > which was caused by calling strlcpy() (which in turn called strlen()) > on the user-supplied non-terminated string. > > Signed-off-by: Alexander Potapenko We should not be allowing non-NULL terminated strings for the IFLA_IFALIAS attribute. It's defined as type NLA_STRING in the ifla_policy[] array. Please figure out why we aren't enforcing the attribute policy properly, rather than adding a workaround. Thanks.