diff --git a/net/tcp/tcp_wrbuffer.c b/net/tcp/tcp_wrbuffer.c
index f8d0a09de8..c0eb6bfe4f 100644
--- a/net/tcp/tcp_wrbuffer.c
+++ b/net/tcp/tcp_wrbuffer.c
@@ -40,7 +40,6 @@
  ****************************************************************************/
 
 #include <nuttx/net/netconfig.h>
-#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) && defined(CONFIG_NET_TCP_WRITE_BUFFERS)
 
 #if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_NET_TCP_WRBUFFER_DEBUG)
 /* Force debug output (from this file only) */
@@ -59,8 +58,11 @@
 #include <nuttx/net/net.h>
 #include <nuttx/mm/iob.h>
 
+#include "utils/utils.h"
 #include "tcp/tcp.h"
 
+#if defined(CONFIG_NET_TCP) && defined(CONFIG_NET_TCP_WRITE_BUFFERS)
+
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -159,8 +161,29 @@ FAR struct tcp_wrbuffer_s *tcp_wrbuffer_alloc(void)
 
   /* Now get the first I/O buffer for the write buffer structure */
 
-  wrb->wb_iob = iob_alloc(false);
-  if (!wrb->wb_iob)
+  wrb->wb_iob = iob_tryalloc(false);
+  if (wrb->wb_iob == NULL)
+    {
+      unsigned int count;
+      int ret;
+
+      /* There are no buffers available now.  We will have to wait for one to
+       * become available. But let's not do that with the network locked.
+       */
+
+      ret = net_breaklock(&count);
+      wrb->wb_iob = iob_alloc(false);
+      if (ret >= 0)
+        {
+          net_restorelock(count);
+        }
+    }
+
+  /* Did we get an IOB?  We should always get one except under some really weird
+   * error conditions.
+   */
+
+  if (wrb->wb_iob == NULL)
     {
       nerr("ERROR: Failed to allocate I/O buffer\n");
       tcp_wrbuffer_release(wrb);
@@ -284,4 +307,4 @@ int tcp_wrbuffer_test(void)
   return ret;
 }
 
-#endif /* CONFIG_NET && CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */
+#endif /* CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */
diff --git a/net/utils/net_lock.c b/net/utils/net_lock.c
index 3bf9128ade..6b32062c5f 100644
--- a/net/utils/net_lock.c
+++ b/net/utils/net_lock.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/utils/net_lock.c
  *
- *   Copyright (C) 2011-2012, 2014-2017 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2012, 2014-2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -204,6 +204,64 @@ void net_unlock(void)
 #endif
 }
 
+/****************************************************************************
+ * Name: net_breaklock
+ *
+ * Description:
+ *   Break the lock, return information needed to restore re-entrant lock
+ *   state.
+ *
+ ****************************************************************************/
+
+int net_breaklock(FAR unsigned int *count)
+{
+  irqstate_t flags;
+  pid_t me = getpid();
+  int ret = -EPERM;
+
+  DEBUGASSERT(count != NULL);
+
+  flags = spin_lock_irqsave(); /* No interrupts */
+  if (g_holder == me)
+    {
+      /* Return the lock setting */
+
+      *count   = g_count;
+
+      /* Release the network lock  */
+
+      g_holder = NO_HOLDER;
+      g_count  = 0;
+
+      (void)nxsem_post(&g_netlock);
+      ret      = OK;
+    }
+
+  spin_unlock_irqrestore(flags);
+  return ret;
+}
+
+/****************************************************************************
+ * Name: net_breaklock
+ *
+ * Description:
+ *   Restore the locked state
+ *
+ ****************************************************************************/
+
+void net_restorelock(unsigned int count)
+{
+  pid_t me = getpid();
+
+  DEBUGASSERT(g_holder != me);
+
+  /* Recover the network lock at the proper count */
+
+  _net_takesem();
+  g_holder = me;
+  g_count  = count;
+}
+
 /****************************************************************************
  * Name: net_timedwait
  *
diff --git a/net/utils/utils.h b/net/utils/utils.h
index ddbbff1aa8..75d1dd8904 100644
--- a/net/utils/utils.h
+++ b/net/utils/utils.h
@@ -86,6 +86,27 @@ struct timeval;           /* Forward reference */
 
 void net_lockinitialize(void);
 
+/****************************************************************************
+ * Name: net_breaklock
+ *
+ * Description:
+ *   Break the lock, return information needed to restore re-entrant lock
+ *   state.
+ *
+ ****************************************************************************/
+
+int net_breaklock(FAR unsigned int *count);
+
+/****************************************************************************
+ * Name: net_breaklock
+ *
+ * Description:
+ *   Restore the locked state
+ *
+ ****************************************************************************/
+
+void net_restorelock(unsigned int count);
+
 /****************************************************************************
  * Name: net_dsec2timeval
  *