From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754489Ab3KAVn5 (ORCPT ); Fri, 1 Nov 2013 17:43:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54500 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751830Ab3KAVnu (ORCPT ); Fri, 1 Nov 2013 17:43:50 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?J=C3=BCri=20Aedla?= , Dan Carpenter , "David S. Miller" Subject: [ 06/32] net: heap overflow in __audit_sockaddr() Date: Fri, 1 Nov 2013 14:43:17 -0700 Message-Id: <20131101214315.263294759@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20131101214313.735463599@linuxfoundation.org> References: <20131101214313.735463599@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Dan Carpenter [ Upstream commit 1661bf364ae9c506bc8795fef70d1532931be1e8 ] We need to cap ->msg_namelen or it leads to a buffer overflow when we to the memcpy() in __audit_sockaddr(). It requires CAP_AUDIT_CONTROL to exploit this bug. The call tree is: ___sys_recvmsg() move_addr_to_user() audit_sockaddr() __audit_sockaddr() Reported-by: Jüri Aedla Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/compat.c | 2 ++ net/socket.c | 24 ++++++++++++++++++++---- 2 files changed, 22 insertions(+), 4 deletions(-) --- a/net/compat.c +++ b/net/compat.c @@ -71,6 +71,8 @@ int get_compat_msghdr(struct msghdr *kms __get_user(kmsg->msg_controllen, &umsg->msg_controllen) || __get_user(kmsg->msg_flags, &umsg->msg_flags)) return -EFAULT; + if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) + return -EINVAL; kmsg->msg_name = compat_ptr(tmp1); kmsg->msg_iov = compat_ptr(tmp2); kmsg->msg_control = compat_ptr(tmp3); --- a/net/socket.c +++ b/net/socket.c @@ -1899,6 +1899,16 @@ struct used_address { unsigned int name_len; }; +static int copy_msghdr_from_user(struct msghdr *kmsg, + struct msghdr __user *umsg) +{ + if (copy_from_user(kmsg, umsg, sizeof(struct msghdr))) + return -EFAULT; + if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) + return -EINVAL; + return 0; +} + static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg, struct msghdr *msg_sys, unsigned flags, struct used_address *used_address) @@ -1917,8 +1927,11 @@ static int ___sys_sendmsg(struct socket if (MSG_CMSG_COMPAT & flags) { if (get_compat_msghdr(msg_sys, msg_compat)) return -EFAULT; - } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr))) - return -EFAULT; + } else { + err = copy_msghdr_from_user(msg_sys, msg); + if (err) + return err; + } /* do not move before msg_sys is valid */ err = -EMSGSIZE; @@ -2129,8 +2142,11 @@ static int ___sys_recvmsg(struct socket if (MSG_CMSG_COMPAT & flags) { if (get_compat_msghdr(msg_sys, msg_compat)) return -EFAULT; - } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr))) - return -EFAULT; + } else { + err = copy_msghdr_from_user(msg_sys, msg); + if (err) + return err; + } err = -EMSGSIZE; if (msg_sys->msg_iovlen > UIO_MAXIOV)