net: synack packets can be attached to request sockets
selinux needs few changes to accommodate fact that SYNACK messages
can be attached to a request socket, lacking sk_security pointer
(Only syncookies are still attached to a TCP_LISTEN socket)
Adds a new sk_listener() helper, and use it in selinux and sch_fq
Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported by: kernel test robot <ying.huang@linux.intel.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sock.h b/include/net/sock.h
index dfe2eb8..771ca19 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2201,6 +2201,14 @@
return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
}
+/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
+ * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
+ */
+static inline bool sk_listener(const struct sock *sk)
+{
+ return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
+}
+
void sock_enable_timestamp(struct sock *sk, int flag);
int sock_get_timestamp(struct sock *, struct timeval __user *);
int sock_get_timestampns(struct sock *, struct timespec __user *);
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 3386cce..109b232 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -225,6 +225,7 @@
return &q->internal;
/* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket
+ * or a listener (SYNCOOKIE mode)
* 1) request sockets are not full blown,
* they do not contain sk_pacing_rate
* 2) They are not part of a 'flow' yet
@@ -232,7 +233,7 @@
* especially if the listener set SO_MAX_PACING_RATE
* 4) We pretend they are orphaned
*/
- if (!sk || sk->sk_state == TCP_NEW_SYN_RECV) {
+ if (!sk || sk_listener(sk)) {
unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
/* By forcing low order bit to 1, we make sure to not
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 6434016..6e50841 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4898,7 +4898,7 @@
if (sk) {
struct sk_security_struct *sksec;
- if (sk->sk_state == TCP_LISTEN)
+ if (sk_listener(sk))
/* if the socket is the listening state then this
* packet is a SYN-ACK packet which means it needs to
* be labeled based on the connection/request_sock and
@@ -5005,7 +5005,7 @@
* unfortunately, this means more work, but it is only once per
* connection. */
if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
- !(sk != NULL && sk->sk_state == TCP_LISTEN))
+ !(sk && sk_listener(sk)))
return NF_ACCEPT;
#endif
@@ -5022,7 +5022,7 @@
secmark_perm = PACKET__SEND;
peer_sid = SECINITSID_KERNEL;
}
- } else if (sk->sk_state == TCP_LISTEN) {
+ } else if (sk_listener(sk)) {
/* Locally generated packet but the associated socket is in the
* listening state which means this is a SYN-ACK packet. In
* this particular case the correct security label is assigned
@@ -5033,7 +5033,11 @@
* selinux_inet_conn_request(). See also selinux_ip_output()
* for similar problems. */
u32 skb_sid;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec;
+
+ if (sk->sk_state == TCP_NEW_SYN_RECV)
+ sk = inet_reqsk(sk)->rsk_listener;
+ sksec = sk->sk_security;
if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
return NF_DROP;
/* At this point, if the returned skb peerlbl is SECSID_NULL