Merge tag 'net-5.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from.. Santa?

  No regressions on our radar at this point. The igc problem fixed here
  was the last one I was tracking but it was broken in previous
  releases, anyway. Mostly driver fixes and a couple of largish SMC
  fixes.

  Current release - regressions:

   - xsk: initialise xskb free_list_node, fixup for a -rc7 fix

  Current release - new code bugs:

   - mlx5: handful of minor fixes:

   - use first online CPU instead of hard coded CPU

   - fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'

   - fix skb memory leak when TC classifier action offloads are disabled

   - fix memory leak with rules with internal OvS port

  Previous releases - regressions:

   - igc: do not enable crosstimestamping for i225-V models

  Previous releases - always broken:

   - udp: use datalen to cap ipv6 udp max gso segments

   - fix use-after-free in tw_timer_handler due to early free of stats

   - smc: fix kernel panic caused by race of smc_sock

   - smc: don't send CDC/LLC message if link not ready, avoid timeouts

   - sctp: use call_rcu to free endpoint, avoid UAF in sock diag

   - bridge: mcast: add and enforce query interval minimum

   - usb: pegasus: do not drop long Ethernet frames

   - mlx5e: fix ICOSQ recovery flow for XSK

   - nfc: uapi: use kernel size_t to fix user-space builds"

* tag 'net-5.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (47 commits)
  fsl/fman: Fix missing put_device() call in fman_port_probe
  selftests: net: using ping6 for IPv6 in udpgro_fwd.sh
  Documentation: fix outdated interpretation of ip_no_pmtu_disc
  net/ncsi: check for error return from call to nla_put_u32
  net: bridge: mcast: fix br_multicast_ctx_vlan_global_disabled helper
  net: fix use-after-free in tw_timer_handler
  selftests: net: Fix a typo in udpgro_fwd.sh
  selftests/net: udpgso_bench_tx: fix dst ip argument
  net: bridge: mcast: add and enforce startup query interval minimum
  net: bridge: mcast: add and enforce query interval minimum
  ipv6: raw: check passed optlen before reading
  xsk: Initialise xskb free_list_node
  net/mlx5e: Fix wrong features assignment in case of error
  net/mlx5e: TC, Fix memory leak with rules with internal port
  ionic: Initialize the 'lif->dbid_inuse' bitmap
  igc: Fix TX timestamp support for non-MSI-X platforms
  igc: Do not enable crosstimestamping for i225-V models
  net/smc: fix kernel panic caused by race of smc_sock
  net/smc: don't send CDC/LLC message if link not ready
  NFC: st21nfca: Fix memory leak in device probe and remove
  ...

3 files changed, 36 insertions, 22 deletions

diff --git a/net/sctp/diag.c b/net/sctp/diag.c
index 760b367644c1..a7d623171501 100644
--- a/net/sctp/diag.c
+++ b/net/sctp/diag.c
@@ -290,9 +290,8 @@ out:
 	return err;
 }
 
-static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
+static int sctp_sock_dump(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
 {
-	struct sctp_endpoint *ep = tsp->asoc->ep;
 	struct sctp_comm_param *commp = p;
 	struct sock *sk = ep->base.sk;
 	struct sk_buff *skb = commp->skb;
@@ -302,6 +301,8 @@ static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
 	int err = 0;
 
 	lock_sock(sk);
+	if (ep != tsp->asoc->ep)
+		goto release;
 	list_for_each_entry(assoc, &ep->asocs, asocs) {
 		if (cb->args[4] < cb->args[1])
 			goto next;
@@ -344,9 +345,8 @@ release:
 	return err;
 }
 
-static int sctp_sock_filter(struct sctp_transport *tsp, void *p)
+static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
 {
-	struct sctp_endpoint *ep = tsp->asoc->ep;
 	struct sctp_comm_param *commp = p;
 	struct sock *sk = ep->base.sk;
 	const struct inet_diag_req_v2 *r = commp->r;
@@ -505,8 +505,8 @@ skip:
 	if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
 		goto done;
 
-	sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
-				net, &pos, &commp);
+	sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump,
+					net, &pos, &commp);
 	cb->args[2] = pos;
 
 done:
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 48c9c2c7602f..efffde7f2328 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -184,6 +184,18 @@ void sctp_endpoint_free(struct sctp_endpoint *ep)
 }
 
 /* Final destructor for endpoint.  */
+static void sctp_endpoint_destroy_rcu(struct rcu_head *head)
+{
+	struct sctp_endpoint *ep = container_of(head, struct sctp_endpoint, rcu);
+	struct sock *sk = ep->base.sk;
+
+	sctp_sk(sk)->ep = NULL;
+	sock_put(sk);
+
+	kfree(ep);
+	SCTP_DBG_OBJCNT_DEC(ep);
+}
+
 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 {
 	struct sock *sk;
@@ -213,18 +225,13 @@ static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 	if (sctp_sk(sk)->bind_hash)
 		sctp_put_port(sk);
 
-	sctp_sk(sk)->ep = NULL;
-	/* Give up our hold on the sock */
-	sock_put(sk);
-
-	kfree(ep);
-	SCTP_DBG_OBJCNT_DEC(ep);
+	call_rcu(&ep->rcu, sctp_endpoint_destroy_rcu);
 }
 
 /* Hold a reference to an endpoint. */
-void sctp_endpoint_hold(struct sctp_endpoint *ep)
+int sctp_endpoint_hold(struct sctp_endpoint *ep)
 {
-	refcount_inc(&ep->base.refcnt);
+	return refcount_inc_not_zero(&ep->base.refcnt);
 }
 
 /* Release a reference to an endpoint and clean up if there are
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 33391254fa82..ad5028a07b18 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -5338,11 +5338,12 @@ int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
 }
 EXPORT_SYMBOL_GPL(sctp_transport_lookup_process);
 
-int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
-			    int (*cb_done)(struct sctp_transport *, void *),
-			    struct net *net, int *pos, void *p) {
+int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done,
+				    struct net *net, int *pos, void *p)
+{
 	struct rhashtable_iter hti;
 	struct sctp_transport *tsp;
+	struct sctp_endpoint *ep;
 	int ret;
 
 again:
@@ -5351,26 +5352,32 @@ again:
 
 	tsp = sctp_transport_get_idx(net, &hti, *pos + 1);
 	for (; !IS_ERR_OR_NULL(tsp); tsp = sctp_transport_get_next(net, &hti)) {
-		ret = cb(tsp, p);
-		if (ret)
-			break;
+		ep = tsp->asoc->ep;
+		if (sctp_endpoint_hold(ep)) { /* asoc can be peeled off */
+			ret = cb(ep, tsp, p);
+			if (ret)
+				break;
+			sctp_endpoint_put(ep);
+		}
 		(*pos)++;
 		sctp_transport_put(tsp);
 	}
 	sctp_transport_walk_stop(&hti);
 
 	if (ret) {
-		if (cb_done && !cb_done(tsp, p)) {
+		if (cb_done && !cb_done(ep, tsp, p)) {
 			(*pos)++;
+			sctp_endpoint_put(ep);
 			sctp_transport_put(tsp);
 			goto again;
 		}
+		sctp_endpoint_put(ep);
 		sctp_transport_put(tsp);
 	}
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(sctp_for_each_transport);
+EXPORT_SYMBOL_GPL(sctp_transport_traverse_process);
 
 /* 7.2.1 Association Status (SCTP_STATUS)