From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753827Ab3FDWnn (ORCPT ); Tue, 4 Jun 2013 18:43:43 -0400 Received: from 1wt.eu ([62.212.114.60]:35745 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753890Ab3FDWnb (ORCPT ); Tue, 4 Jun 2013 18:43:31 -0400 Message-Id: <20130604172137.725419704@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 04 Jun 2013 19:24:29 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mathias Krause , Arnaldo Carvalho de Melo , "David S. Miller" , Greg Kroah-Hartman , Willy Tarreau Subject: [ 179/184] llc: fix info leak via getsockname() In-Reply-To: <58df134a4b98edf5b0073e2e1e988fe6@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm 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 Signed-off-by: Willy Tarreau --- net/llc/af_llc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index 2da8d14..606b6ad 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -912,14 +912,13 @@ static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, 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) -- 1.7.12.2.21.g234cd45.dirty