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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 A01A8C32792 for ; Mon, 30 Sep 2019 15:35:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77230215EA for ; Mon, 30 Sep 2019 15:35:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732083AbfI3Pfq convert rfc822-to-8bit (ORCPT ); Mon, 30 Sep 2019 11:35:46 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([146.101.78.151]:20001 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730809AbfI3Pfq (ORCPT ); Mon, 30 Sep 2019 11:35:46 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-171-6gbYdDGuMiuY3reOFp0ISg-1; Mon, 30 Sep 2019 16:35:43 +0100 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Mon, 30 Sep 2019 16:35:42 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Mon, 30 Sep 2019 16:35:42 +0100 From: David Laight To: 'Denis Efremov' , "linux-wireless@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Pontus Fuchs , Kalle Valo , "David S. Miller" , "stable@vger.kernel.org" Subject: RE: [PATCH] ar5523: check NULL before memcpy() in ar5523_cmd() Thread-Topic: [PATCH] ar5523: check NULL before memcpy() in ar5523_cmd() Thread-Index: AQHVd5eyJR20opeapUCX0TL00aRlGadEWhCg Date: Mon, 30 Sep 2019 15:35:42 +0000 Message-ID: <230cd4f790544b01a26afa26e4186454@AcuMS.aculab.com> References: <20190930140207.28638-1-efremov@linux.com> In-Reply-To: <20190930140207.28638-1-efremov@linux.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-MC-Unique: 6gbYdDGuMiuY3reOFp0ISg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Denis Efremov > Sent: 30 September 2019 15:02 > > memcpy() call with "idata == NULL && ilen == 0" results in undefined > behavior in ar5523_cmd(). For example, NULL is passed in callchain > "ar5523_stat_work() -> ar5523_cmd_write() -> ar5523_cmd()". This patch > adds idata check before memcpy() call in ar5523_cmd() to prevent an > undefined behavior. > ... > Signed-off-by: Denis Efremov > --- > drivers/net/wireless/ath/ar5523/ar5523.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c > index b94759daeacc..f25af5bc5282 100644 > --- a/drivers/net/wireless/ath/ar5523/ar5523.c > +++ b/drivers/net/wireless/ath/ar5523/ar5523.c > @@ -255,7 +255,8 @@ static int ar5523_cmd(struct ar5523 *ar, u32 code, const void *idata, > > if (flags & AR5523_CMD_FLAG_MAGIC) > hdr->magic = cpu_to_be32(1 << 24); > - memcpy(hdr + 1, idata, ilen); > + if (idata) > + memcpy(hdr + 1, idata, ilen); That would be better as if (ilen) ... David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)