From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: [PATCH] net: af_packet: Validate parameter size for PACKET_HDRLEN control message Date: Wed, 27 Feb 2013 11:46:58 -0800 Message-ID: <1361994418-1403-1-git-send-email-linux@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "David S. Miller" , Guenter Roeck To: netdev@vger.kernel.org Return-path: Received: from mail.active-venture.com ([67.228.131.205]:54692 "EHLO mail.active-venture.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752587Ab3B0Tq7 (ORCPT ); Wed, 27 Feb 2013 14:46:59 -0500 Sender: netdev-owner@vger.kernel.org List-ID: Building af_packet may fail with In function =E2=80=98copy_from_user=E2=80=99, inlined from =E2=80=98packet_getsockopt=E2=80=99 at net/packet/af_packet.c:3215:21: arch/x86/include/asm/uaccess_32.h:211:26: error: call to =E2=80=98copy_from_user_overflow=E2=80=99 declared with attribute e= rror: copy_from_user() buffer size is not provably correct if built with W=3D1 due to a missing parameter size validation. Signed-off-by: Guenter Roeck --- net/packet/af_packet.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index c7bfeff..1976b23 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3210,6 +3210,8 @@ static int packet_getsockopt(struct socket *sock,= int level, int optname, val =3D po->tp_version; break; case PACKET_HDRLEN: + if (len < sizeof(int)) + return -EINVAL; if (len > sizeof(int)) len =3D sizeof(int); if (copy_from_user(&val, optval, len)) --=20 1.7.9.7