From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: [PATCH net] ip: zero sockaddr returned on error queue Date: Thu, 15 Jan 2015 13:18:40 -0500 Message-ID: <1421345920-13994-1-git-send-email-willemb@google.com> Cc: davem@davemloft.net, Willem de Bruijn To: netdev@vger.kernel.org Return-path: Received: from mail-yh0-f50.google.com ([209.85.213.50]:62099 "EHLO mail-yh0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752247AbbAOSSy (ORCPT ); Thu, 15 Jan 2015 13:18:54 -0500 Received: by mail-yh0-f50.google.com with SMTP id b6so8004835yha.9 for ; Thu, 15 Jan 2015 10:18:53 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: From: Willem de Bruijn The sockaddr is returned in IP(V6)_RECVERR as part of errhdr. That structure is defined and allocated on the stack as struct { struct sock_extended_err ee; struct sockaddr_in(6) offender; } errhdr; The second part is only initialized for certain SO_EE_ORIGIN values. Always initialize it completely. An MTU exceeded error on a SOCK_RAW/IPPROTO_RAW is one example that would return uninitialized bytes. Signed-off-by: Willem de Bruijn ---- Also verified that there is no padding between errhdr.ee and errhdr.offender that could leak additional kernel data. --- net/ipv4/ip_sockglue.c | 8 ++------ net/ipv6/datagram.c | 10 +++------- 2 files changed, 5 insertions(+), 13 deletions(-) diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 8a89c73..6b85adb 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -461,17 +461,13 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); sin = &errhdr.offender; - sin->sin_family = AF_UNSPEC; + memset(sin, 0, sizeof(*sin)); if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP || ipv4_pktinfo_prepare_errqueue(sk, skb, serr->ee.ee_origin)) { - struct inet_sock *inet = inet_sk(sk); - sin->sin_family = AF_INET; sin->sin_addr.s_addr = ip_hdr(skb)->saddr; - sin->sin_port = 0; - memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); - if (inet->cmsg_flags) + if (inet_sk(sk)->cmsg_flags) ip_cmsg_recv(msg, skb); } diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c index 100c589..49f5e73 100644 --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -393,11 +393,10 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); sin = &errhdr.offender; - sin->sin6_family = AF_UNSPEC; + memset(sin, 0, sizeof(*sin)); + if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) { sin->sin6_family = AF_INET6; - sin->sin6_flowinfo = 0; - sin->sin6_port = 0; if (np->rxopt.all) { if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP && serr->ee.ee_origin != SO_EE_ORIGIN_ICMP6) @@ -412,12 +411,9 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) ipv6_iface_scope_id(&sin->sin6_addr, IP6CB(skb)->iif); } else { - struct inet_sock *inet = inet_sk(sk); - ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &sin->sin6_addr); - sin->sin6_scope_id = 0; - if (inet->cmsg_flags) + if (inet_sk(sk)->cmsg_flags) ip_cmsg_recv(msg, skb); } } -- 2.2.0.rc0.207.ga3a616c