From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F5B270 for ; Mon, 14 Jun 2021 20:48:50 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-65-ON67q3ytPwmYheTyY52QOw-1; Mon, 14 Jun 2021 21:48:46 +0100 X-MC-Unique: ON67q3ytPwmYheTyY52QOw-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Mon, 14 Jun 2021 21:48:45 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.018; Mon, 14 Jun 2021 21:48:45 +0100 From: David Laight To: 'Jhih-Ming Huang' , "gregkh@linuxfoundation.org" , "fabioaiuto83@gmail.com" , "ross.schm.dev@gmail.com" , "maqianga@uniontech.com" , "marcocesati@gmail.com" , "linux-staging@lists.linux.dev" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] rtw_security: fix cast to restricted __le32 Thread-Topic: [PATCH] rtw_security: fix cast to restricted __le32 Thread-Index: AQHXYD46HyWlcwiQGkiXWqpP7mZmBasT+umQ Date: Mon, 14 Jun 2021 20:48:45 +0000 Message-ID: <8974a58823d74d118595d4f8db5ac870@AcuMS.aculab.com> References: <20210613102229.1424495-1-fbihjmeric@gmail.com> In-Reply-To: <20210613102229.1424495-1-fbihjmeric@gmail.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable From: Jhih-Ming Huang > Sent: 13 June 2021 11:22 >=20 > This patch fixes the sparse warning of fix cast to restricted __le32. >=20 > Signed-off-by: Jhih-Ming Huang > --- > drivers/staging/rtl8723bs/core/rtw_security.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/staging/rtl8723bs/core/rtw_security.c > b/drivers/staging/rtl8723bs/core/rtw_security.c > index a99f439328f1..2f4da67e31c6 100644 > --- a/drivers/staging/rtl8723bs/core/rtw_security.c > +++ b/drivers/staging/rtl8723bs/core/rtw_security.c > @@ -121,7 +121,7 @@ void rtw_wep_decrypt(struct adapter *padapter, u8 *p= recvframe) > =09=09arc4_crypt(ctx, payload, payload, length); >=20 > =09=09/* calculate icv and compare the icv */ > -=09=09*((u32 *)crc) =3D le32_to_cpu(~crc32_le(~0, payload, length - 4)); > +=09=09*((u32 *)crc) =3D le32_to_cpu((__force __le32)~crc32_le(~0, payloa= d, length - 4)); >=20 > =09} > } > @@ -618,7 +618,8 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, u8 *pr= ecvframe) > =09=09=09arc4_setkey(ctx, rc4key, 16); > =09=09=09arc4_crypt(ctx, payload, payload, length); Is someone using 'rc4' and 'security' in the same file? >=20 > -=09=09=09*((u32 *)crc) =3D le32_to_cpu(~crc32_le(~0, payload, length - 4= )); > +=09=09=09*((u32 *)crc) =3D le32_to_cpu((__force __le32)~crc32_le(~0, pay= load, > +=09=09=09=09=09=09length - 4)); >=20 > =09=09=09if (crc[3] !=3D payload[length - 1] || crc[2] !=3D payload[leng= th - 2] || > =09=09=09 crc[1] !=3D payload[length - 3] || crc[0] !=3D payload[leng= th - 4]) In both cases the *((u32 *)crc) is also very dubious. Casts of pointers to integer types are almost always broken. Given the code that follows the second hunk I'm guessing you have 'u8 crc[4];' (or equivalent). That can be misaligned and then access will panic on some systems. There is a get_unaligned_be32() (or something similar) that can be used to read the crc from (payload + length - 4). =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)