From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946023Ab2I1V6F (ORCPT ); Fri, 28 Sep 2012 17:58:05 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:43081 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031675Ab2I1UW0 (ORCPT ); Fri, 28 Sep 2012 16:22:26 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Mathias Krause , Arnaldo Carvalho de Melo , "David S. Miller" Subject: [ 018/218] llc: fix info leak via getsockname() Date: Fri, 28 Sep 2012 13:13:55 -0700 Message-Id: <20120928201503.404775823@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.1.428.g652398a In-Reply-To: <20120928201501.208384923@linuxfoundation.org> References: <20120928201501.208384923@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Krause [ Upstream commit 3592aaeb80290bda0f2cf0b5456c97bfc638b192 ] The LLC code wrongly returns 0, i.e. "success", when the socket is zapped. Together with the uninitialized uaddrlen pointer argument from sys_getsockname this leads to an arbitrary memory leak of up to 128 bytes kernel stack via the getsockname() syscall. Return an error instead when the socket is zapped to prevent the info leak. Also remove the unnecessary memset(0). We don't directly write to the memory pointed by uaddr but memcpy() a local structure at the end of the function that is properly initialized. Signed-off-by: Mathias Krause Cc: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/llc/af_llc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -971,14 +971,13 @@ static int llc_ui_getname(struct socket struct sockaddr_llc sllc; struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); - int rc = 0; + int rc = -EBADF; memset(&sllc, 0, sizeof(sllc)); lock_sock(sk); if (sock_flag(sk, SOCK_ZAPPED)) goto out; *uaddrlen = sizeof(sllc); - memset(uaddr, 0, *uaddrlen); if (peer) { rc = -ENOTCONN; if (sk->sk_state != TCP_ESTABLISHED)