Merge tag 'net-6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netHEADmaster

Pull networking fixes from Paolo Abeni:
 "Including fixes from Bluetooth.

  Current release - regressions:

   - tcp: refine sk_rcvbuf increase for ooo packets

   - bluetooth: fix attempting to send HCI_Disconnect to BIS handle

   - rxrpc: fix over large frame size warning

   - eth: bcmgenet: initialize u64 stats seq counter

  Previous releases - regressions:

   - tcp: correct signedness in skb remaining space calculation

   - sched: abort __tc_modify_qdisc if parent class does not exist

   - vsock: fix transport_{g2h,h2g} TOCTOU

   - rxrpc: fix bug due to prealloc collision

   - tipc: fix use-after-free in tipc_conn_close().

   - bluetooth: fix not marking Broadcast Sink BIS as connected

   - phy: qca808x: fix WoL issue by utilizing at8031_set_wol()

   - eth: am65-cpsw-nuss: fix skb size by accounting for skb_shared_info

  Previous releases - always broken:

   - netlink: fix wraparounds of sk->sk_rmem_alloc.

   - atm: fix infinite recursive call of clip_push().

   - eth:
      - stmmac: fix interrupt handling for level-triggered mode in DWC_XGMAC2
      - rtsn: fix a null pointer dereference in rtsn_probe()"

* tag 'net-6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (37 commits)
  net/sched: sch_qfq: Fix null-deref in agg_dequeue
  rxrpc: Fix oops due to non-existence of prealloc backlog struct
  rxrpc: Fix bug due to prealloc collision
  MAINTAINERS: remove myself as netronome maintainer
  selftests/net: packetdrill: add tcp_ooo-before-and-after-accept.pkt
  tcp: refine sk_rcvbuf increase for ooo packets
  net/sched: Abort __tc_modify_qdisc if parent class does not exist
  net: ethernet: ti: am65-cpsw-nuss: Fix skb size by accounting for skb_shared_info
  net: thunderx: avoid direct MTU assignment after WRITE_ONCE()
  selftests/tc-testing: Create test case for UAF scenario with DRR/NETEM/BLACKHOLE chain
  atm: clip: Fix NULL pointer dereference in vcc_sendmsg()
  atm: clip: Fix infinite recursive call of clip_push().
  atm: clip: Fix memory leak of struct clip_vcc.
  atm: clip: Fix potential null-ptr-deref in to_atmarpd().
  net: phy: smsc: Fix link failure in forced mode with Auto-MDIX
  net: phy: smsc: Force predictable MDI-X state on LAN87xx
  net: phy: smsc: Fix Auto-MDIX configuration when disabled by strap
  net: stmmac: Fix interrupt handling for level-triggered mode in DWC_XGMAC2
  rxrpc: Fix over large frame size warning
  net: airoha: Fix an error handling path in airoha_probe()
  ...

1 files changed, 46 insertions, 11 deletions

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 2e7a3034e965..1053662725f8 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -407,6 +407,8 @@ EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 
 static bool vsock_use_local_transport(unsigned int remote_cid)
 {
+	lockdep_assert_held(&vsock_register_mutex);
+
 	if (!transport_local)
 		return false;
 
@@ -464,6 +466,8 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 
 	remote_flags = vsk->remote_addr.svm_flags;
 
+	mutex_lock(&vsock_register_mutex);
+
 	switch (sk->sk_type) {
 	case SOCK_DGRAM:
 		new_transport = transport_dgram;
@@ -479,12 +483,15 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 			new_transport = transport_h2g;
 		break;
 	default:
-		return -ESOCKTNOSUPPORT;
+		ret = -ESOCKTNOSUPPORT;
+		goto err;
 	}
 
 	if (vsk->transport) {
-		if (vsk->transport == new_transport)
-			return 0;
+		if (vsk->transport == new_transport) {
+			ret = 0;
+			goto err;
+		}
 
 		/* transport->release() must be called with sock lock acquired.
 		 * This path can only be taken during vsock_connect(), where we
@@ -508,8 +515,16 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 	/* We increase the module refcnt to prevent the transport unloading
 	 * while there are open sockets assigned to it.
 	 */
-	if (!new_transport || !try_module_get(new_transport->module))
-		return -ENODEV;
+	if (!new_transport || !try_module_get(new_transport->module)) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	/* It's safe to release the mutex after a successful try_module_get().
+	 * Whichever transport `new_transport` points at, it won't go away until
+	 * the last module_put() below or in vsock_deassign_transport().
+	 */
+	mutex_unlock(&vsock_register_mutex);
 
 	if (sk->sk_type == SOCK_SEQPACKET) {
 		if (!new_transport->seqpacket_allow ||
@@ -528,12 +543,31 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 	vsk->transport = new_transport;
 
 	return 0;
+err:
+	mutex_unlock(&vsock_register_mutex);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(vsock_assign_transport);
 
+/*
+ * Provide safe access to static transport_{h2g,g2h,dgram,local} callbacks.
+ * Otherwise we may race with module removal. Do not use on `vsk->transport`.
+ */
+static u32 vsock_registered_transport_cid(const struct vsock_transport **transport)
+{
+	u32 cid = VMADDR_CID_ANY;
+
+	mutex_lock(&vsock_register_mutex);
+	if (*transport)
+		cid = (*transport)->get_local_cid();
+	mutex_unlock(&vsock_register_mutex);
+
+	return cid;
+}
+
 bool vsock_find_cid(unsigned int cid)
 {
-	if (transport_g2h && cid == transport_g2h->get_local_cid())
+	if (cid == vsock_registered_transport_cid(&transport_g2h))
 		return true;
 
 	if (transport_h2g && cid == VMADDR_CID_HOST)
@@ -2536,18 +2570,19 @@ static long vsock_dev_do_ioctl(struct file *filp,
 			       unsigned int cmd, void __user *ptr)
 {
 	u32 __user *p = ptr;
-	u32 cid = VMADDR_CID_ANY;
 	int retval = 0;
+	u32 cid;
 
 	switch (cmd) {
 	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
 		/* To be compatible with the VMCI behavior, we prioritize the
 		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).
 		 */
-		if (transport_g2h)
-			cid = transport_g2h->get_local_cid();
-		else if (transport_h2g)
-			cid = transport_h2g->get_local_cid();
+		cid = vsock_registered_transport_cid(&transport_g2h);
+		if (cid == VMADDR_CID_ANY)
+			cid = vsock_registered_transport_cid(&transport_h2g);
+		if (cid == VMADDR_CID_ANY)
+			cid = vsock_registered_transport_cid(&transport_local);
 
 		if (put_user(cid, p) != 0)
 			retval = -EFAULT;