From f8687afefcc821fc47c75775eec87731fe3de360 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 30 Oct 2006 15:22:15 -0800 Subject: [NetLabel]: protect the CIPSOv4 socket option from setsockopt() This patch makes two changes to protect applications from either removing or tampering with the CIPSOv4 IP option on a socket. The first is the requirement that applications have the CAP_NET_RAW capability to set an IPOPT_CIPSO option on a socket; this prevents untrusted applications from setting their own CIPSOv4 security attributes on the packets they send. The second change is to SELinux and it prevents applications from setting any IPv4 options when there is an IPOPT_CIPSO option already present on the socket; this prevents applications from removing CIPSOv4 security attributes from the packets they send. Signed-off-by: Paul Moore Signed-off-by: James Morris Signed-off-by: David S. Miller --- net/ipv4/cipso_ipv4.c | 7 +++---- net/ipv4/ip_options.c | 2 +- 2 files changed, 4 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index e2077a3aa8c0..6460233407c7 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1307,7 +1307,8 @@ int cipso_v4_socket_setattr(const struct socket *sock, /* We can't use ip_options_get() directly because it makes a call to * ip_options_get_alloc() which allocates memory with GFP_KERNEL and - * we can't block here. */ + * we won't always have CAP_NET_RAW even though we _always_ want to + * set the IPOPT_CIPSO option. */ opt_len = (buf_len + 3) & ~3; opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); if (opt == NULL) { @@ -1317,11 +1318,9 @@ int cipso_v4_socket_setattr(const struct socket *sock, memcpy(opt->__data, buf, buf_len); opt->optlen = opt_len; opt->is_data = 1; + opt->cipso = sizeof(struct iphdr); kfree(buf); buf = NULL; - ret_val = ip_options_compile(opt, NULL); - if (ret_val != 0) - goto socket_setattr_failure; sk_inet = inet_sk(sk); if (sk_inet->is_icsk) { diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index 8dabbfc31267..9f02917d6f45 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -443,7 +443,7 @@ int ip_options_compile(struct ip_options * opt, struct sk_buff * skb) opt->router_alert = optptr - iph; break; case IPOPT_CIPSO: - if (opt->cipso) { + if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) { pp_ptr = optptr; goto error; } -- cgit v1.2.2