A JavaSE licensee's customer faces with serious crash because of exhaustion of native heap.
This crash seems caused by lack of free operation for InputStream read buffer(native).

INVESTIGATION:
The following source code portion is extracted from jdk7b76.

==== ./jdk/src/windows/native/java/net/SocketInputStream.c ===>
........
    60 JNIEXPORT jint JNICALL
    61 Java_java_net_SocketInputStream_socketRead0(JNIEnv *env, jobject this,
    62 jobject fdObj, jbyteArray data,
    63 jint off, jint len, jint timeout
    64 {
    65 char *bufP;
    66 char BUF[MAX_BUFFER_LEN];
    67 jint fd, newfd;
    68 jint nread;
    69
    70 if (IS_NULL(fdObj)) {
    71 JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", "socket closed");
    72 return -1;
    73 }
    74 fd = (*env)->GetIntField(env, fdObj, IO_fd_fdID);
    75 if (fd == -1) {
    76 NET_ThrowSocketException(env, "Socket closed");
    77 return -1;
    78 }
    79
    80 /*
    81 * If the caller buffer is large than our stack buffer then we allocate
    82 * from the heap (up to a limit). If memory is exhausted we always use
    83 * the stack buffer.
    84 */
    85 if (len <= MAX_BUFFER_LEN) {
    86 bufP = BUF;
    87 } else {
    88 if (len > MAX_HEAP_BUFFER_LEN) {
    89 len = MAX_HEAP_BUFFER_LEN;
    90 }
    91 bufP = (char *)malloc((size_t)len); // <==== Allocating Buffer
    92 if (bufP == NULL) {
    93 /* allocation failed so use stack buffer */
    94 bufP = BUF;
    95 len = MAX_BUFFER_LEN;
    96 }
    97 }
    98
    99
   100 if (timeout) {
   101 if (timeout <= 5000 || !isRcvTimeoutSupported) {
   102 int ret = NET_Timeout (fd, timeout);
   103
   104 if (ret <= 0) {
   105 if (ret == 0) {
   106 JNU_ThrowByName(env, JNU_JAVANETPKG "SocketTimeoutException",
   107 "Read timed out");
   108 } else if (ret == JVM_IO_ERR) {
   109 JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", "socket closed");
   110 } else if (ret == JVM_IO_INTR) {
   111 JNU_ThrowByName(env, JNU_JAVAIOPKG "InterruptedIOException",
   112 "Operation interrupted");
   113 }
   114 if (bufP != BUF) {
   115 free(bufP);
   116 }
   117 return -1;
   118 }
   119
   120 /*check if the socket has been closed while we were in timeout*/
   121 newfd = (*env)->GetIntField(env, fdObj, IO_fd_fdID);
   122 if (newfd == -1) {
   123 NET_ThrowSocketException(env, "Socket Closed");
   124 return -1; // <==== free(bufP) seems needed !
   125 }
   126 }
   127 }

.........
<================================================================


Allocated memory area at line#71 doesn't seem freed when the program exits at line#124.
This program flow path seems cause memory(native heap) leak.
Actually, when the program exits at other "return"s (ex. line#114-117),
allocated bufPs are freed.


CONFIGURATION:
  JDK: jdk7b76/jdk6ux/jdk5ux
       (the latest verions of the above 3 have the same source code portion.)
  OS : WindowsXP/Vista/2008