Merge: sctp: stable backport for 9.7 phase 2

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/6735

JIRA: https://issues.redhat.com/browse/RHEL-84590
Tested: compile only

Signed-off-by: Xin Long <lxin@redhat.com>

Approved-by: Davide Caratti <dcaratti@redhat.com>
Approved-by: Florian Westphal <fwestpha@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>

Author: caringi

include/net/sctp/structs.h

@@ -775,6 +775,7 @@ struct sctp_transport {
 
 	/* Reference counting. */
 	refcount_t refcnt;
+	__u32	dead:1,
 		/* RTO-Pending : A flag used to track if one of the DATA
 		 *		chunks sent to this address is currently being
 		 *		used to compute a RTT. If this flag is 0,
@@ -784,7 +785,7 @@ struct sctp_transport {
 		 *		calculation completes (i.e. the DATA chunk
 		 *		is SACK'd) clear this flag.
 		 */
-	__u32	rto_pending:1,
+		rto_pending:1,
 
 		/*
 		 * hb_sent : a flag that signals that we have a pending

net/sctp/socket.c

@@ -72,8 +72,9 @@
 /* Forward declarations for internal helper functions. */
 static bool sctp_writeable(const struct sock *sk);
 static void sctp_wfree(struct sk_buff *skb);
-static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
-				size_t msg_len);
+static int sctp_wait_for_sndbuf(struct sctp_association *asoc,
+				struct sctp_transport *transport,
+				long *timeo_p, size_t msg_len);
 static int sctp_wait_for_packet(struct sock *sk, int *err, long *timeo_p);
 static int sctp_wait_for_connect(struct sctp_association *, long *timeo_p);
 static int sctp_wait_for_accept(struct sock *sk, long timeo);
@@ -1828,7 +1829,7 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
 
 	if (sctp_wspace(asoc) <= 0 || !sk_wmem_schedule(sk, msg_len)) {
 		timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
-		err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
+		err = sctp_wait_for_sndbuf(asoc, transport, &timeo, msg_len);
 		if (err)
 			goto err;
 		if (unlikely(sinfo->sinfo_stream >= asoc->stream.outcnt)) {
@@ -9214,8 +9215,9 @@ void sctp_sock_rfree(struct sk_buff *skb)
 
 
 /* Helper function to wait for space in the sndbuf.  */
-static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
-				size_t msg_len)
+static int sctp_wait_for_sndbuf(struct sctp_association *asoc,
+				struct sctp_transport *transport,
+				long *timeo_p, size_t msg_len)
 {
 	struct sock *sk = asoc->base.sk;
 	long current_timeo = *timeo_p;
@@ -9225,7 +9227,9 @@ static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
 	pr_debug("%s: asoc:%p, timeo:%ld, msg_len:%zu\n", __func__, asoc,
 		 *timeo_p, msg_len);
 
-	/* Increment the association's refcnt.  */
+	/* Increment the transport and association's refcnt. */
+	if (transport)
+		sctp_transport_hold(transport);
 	sctp_association_hold(asoc);
 
 	/* Wait on the association specific sndbuf space. */
@@ -9234,7 +9238,7 @@ static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
 					  TASK_INTERRUPTIBLE);
 		if (asoc->base.dead)
 			goto do_dead;
-		if (!*timeo_p)
+		if ((!*timeo_p) || (transport && transport->dead))
 			goto do_nonblock;
 		if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING)
 			goto do_error;
@@ -9259,7 +9263,9 @@ static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
 out:
 	finish_wait(&asoc->wait, &wait);
 
-	/* Release the association's refcnt.  */
+	/* Release the transport and association's refcnt. */
+	if (transport)
+		sctp_transport_put(transport);
 	sctp_association_put(asoc);
 
 	return err;

net/sctp/sysctl.c

@@ -391,7 +391,8 @@ static struct ctl_table sctp_net_table[] = {
 static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
 				 void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = container_of(ctl->data, struct net,
+				       sctp.sctp_hmac_alg);
 	struct ctl_table tbl;
 	bool changed = false;
 	char *none = "none";
@@ -436,7 +437,7 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
 static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = container_of(ctl->data, struct net, sctp.rto_min);
 	unsigned int min = *(unsigned int *) ctl->extra1;
 	unsigned int max = *(unsigned int *) ctl->extra2;
 	struct ctl_table tbl;
@@ -464,7 +465,7 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
 static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = container_of(ctl->data, struct net, sctp.rto_max);
 	unsigned int min = *(unsigned int *) ctl->extra1;
 	unsigned int max = *(unsigned int *) ctl->extra2;
 	struct ctl_table tbl;
@@ -502,7 +503,7 @@ static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
 			     void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = container_of(ctl->data, struct net, sctp.auth_enable);
 	struct ctl_table tbl;
 	int new_value, ret;
 
@@ -528,10 +529,12 @@ static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
 	return ret;
 }
 
+static DEFINE_MUTEX(sctp_sysctl_mutex);
+
 static int proc_sctp_do_udp_port(struct ctl_table *ctl, int write,
 				 void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = container_of(ctl->data, struct net, sctp.udp_port);
 	unsigned int min = *(unsigned int *)ctl->extra1;
 	unsigned int max = *(unsigned int *)ctl->extra2;
 	struct ctl_table tbl;
@@ -552,6 +555,7 @@ static int proc_sctp_do_udp_port(struct ctl_table *ctl, int write,
 		if (new_value > max || new_value < min)
 			return -EINVAL;
 
+		mutex_lock(&sctp_sysctl_mutex);
 		net->sctp.udp_port = new_value;
 		sctp_udp_sock_stop(net);
 		if (new_value) {
@@ -564,6 +568,7 @@ static int proc_sctp_do_udp_port(struct ctl_table *ctl, int write,
 		lock_sock(sk);
 		sctp_sk(sk)->udp_port = htons(net->sctp.udp_port);
 		release_sock(sk);
+		mutex_unlock(&sctp_sysctl_mutex);
 	}
 
 	return ret;
@@ -572,7 +577,8 @@ static int proc_sctp_do_udp_port(struct ctl_table *ctl, int write,
 static int proc_sctp_do_probe_interval(struct ctl_table *ctl, int write,
 				       void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = container_of(ctl->data, struct net,
+				       sctp.probe_interval);
 	struct ctl_table tbl;
 	int ret, new_value;
 

net/sctp/transport.c

@@ -117,6 +117,8 @@ struct sctp_transport *sctp_transport_new(struct net *net,
  */
 void sctp_transport_free(struct sctp_transport *transport)
 {
+	transport->dead = 1;
+
 	/* Try to delete the heartbeat timer.  */
 	if (del_timer(&transport->hb_timer))
 		sctp_transport_put(transport);