lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <1365479891.3887.99.camel@edumazet-glaptop>
Date:	Mon, 08 Apr 2013 20:58:11 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Paul Moore <pmoore@...hat.com>
Cc:	David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
	mvadkert@...hat.com, linux-security-module@...r.kernel.org
Subject: [PATCH] selinux: add a skb_owned_by() hook

From: Eric Dumazet <edumazet@...gle.com>

Commit 90ba9b1986b5ac (tcp: tcp_make_synack() can use alloc_skb())
broke certain SELinux/NetLabel configurations by no longer correctly
assigning the sock to the outgoing SYNACK packet.

Cost of atomic operations on the LISTEN socket is quite big,
and we would like it to happen only if really needed.

This patch introduces a new security_ops->skb_owned_by() method,
that is a void operation unless selinux is active.

Reported-by: Miroslav Vadkerti <mvadkert@...hat.com>
Diagnosed-by: Paul Moore <pmoore@...hat.com>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: linux-security-module@...r.kernel.org
---
 include/linux/security.h |    8 ++++++++
 net/ipv4/tcp_output.c    |    1 +
 security/capability.c    |    6 ++++++
 security/security.c      |    5 +++++
 security/selinux/hooks.c |    7 +++++++
 5 files changed, 27 insertions(+)

diff --git a/include/linux/security.h b/include/linux/security.h
index eee7478..6c3a78a 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1638,6 +1638,7 @@ struct security_operations {
 	int (*tun_dev_attach_queue) (void *security);
 	int (*tun_dev_attach) (struct sock *sk, void *security);
 	int (*tun_dev_open) (void *security);
+	void (*skb_owned_by) (struct sk_buff *skb, struct sock *sk);
 #endif	/* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
@@ -2588,6 +2589,8 @@ int security_tun_dev_attach_queue(void *security);
 int security_tun_dev_attach(struct sock *sk, void *security);
 int security_tun_dev_open(void *security);
 
+void security_skb_owned_by(struct sk_buff *skb, struct sock *sk);
+
 #else	/* CONFIG_SECURITY_NETWORK */
 static inline int security_unix_stream_connect(struct sock *sock,
 					       struct sock *other,
@@ -2779,6 +2782,11 @@ static inline int security_tun_dev_open(void *security)
 {
 	return 0;
 }
+
+static inline void security_skb_owned_by(struct sk_buff *skb, struct sock *sk)
+{
+}
+
 #endif	/* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 5d0b438..b44cf81 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2709,6 +2709,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	skb_reserve(skb, MAX_TCP_HEADER);
 
 	skb_dst_set(skb, dst);
+	security_skb_owned_by(skb, sk);
 
 	mss = dst_metric_advmss(dst);
 	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
diff --git a/security/capability.c b/security/capability.c
index 5797750..c36cca6 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -737,6 +737,11 @@ static int cap_tun_dev_open(void *security)
 {
 	return 0;
 }
+
+static void cap_skb_owned_by(struct sk_buff *skb, struct sock *sk) 
+{
+}
+
 #endif	/* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
@@ -1071,6 +1076,7 @@ void __init security_fixup_ops(struct security_operations *ops)
 	set_to_cap_if_null(ops, tun_dev_open);
 	set_to_cap_if_null(ops, tun_dev_attach_queue);
 	set_to_cap_if_null(ops, tun_dev_attach);
+	set_to_cap_if_null(ops, skb_owned_by);
 #endif	/* CONFIG_SECURITY_NETWORK */
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 	set_to_cap_if_null(ops, xfrm_policy_alloc_security);
diff --git a/security/security.c b/security/security.c
index 7b88c6a..03f248b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1290,6 +1290,11 @@ int security_tun_dev_open(void *security)
 }
 EXPORT_SYMBOL(security_tun_dev_open);
 
+void security_skb_owned_by(struct sk_buff *skb, struct sock *sk)
+{
+	security_ops->skb_owned_by(skb, sk);
+}
+
 #endif	/* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 2fa28c8..7171a95 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -51,6 +51,7 @@
 #include <linux/tty.h>
 #include <net/icmp.h>
 #include <net/ip.h>		/* for local_port_range[] */
+#include <net/sock.h>
 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
 #include <net/net_namespace.h>
 #include <net/netlabel.h>
@@ -4363,6 +4364,11 @@ static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
 }
 
+static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
+{
+	skb_set_owner_w(skb, sk);
+}
+
 static int selinux_secmark_relabel_packet(u32 sid)
 {
 	const struct task_security_struct *__tsec;
@@ -5664,6 +5670,7 @@ static struct security_operations selinux_ops = {
 	.tun_dev_attach_queue =		selinux_tun_dev_attach_queue,
 	.tun_dev_attach =		selinux_tun_dev_attach,
 	.tun_dev_open =			selinux_tun_dev_open,
+	.skb_owned_by =			selinux_skb_owned_by,
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 	.xfrm_policy_alloc_security =	selinux_xfrm_policy_alloc,


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ