Crash problem in net.dll

[Jonathan Lu]

Hi Michael,

Thanks for reminding, I checked the source under src/windows folder and 
found two more places to change.

Here's the updated patch:

diff -r 9b8c96f96a0f src/windows/native/java/net/NetworkInterface.c
--- a/src/windows/native/java/net/NetworkInterface.c    Mon Jun 27 
13:21:34 2011 -0700
+++ b/src/windows/native/java/net/NetworkInterface.c    Mon Aug 29 
17:02:56 2011 +0800
@@ -504,8 +504,7 @@
       */
      if (netaddrCount < 0) {
          netaddrCount = enumAddresses_win(env, ifs, &netaddrP);
-        if ((*env)->ExceptionOccurred(env)) {
-            free_netaddr(netaddrP);
+        if (netaddrCount == -1) {
              return NULL;
          }
      }
diff -r 9b8c96f96a0f src/windows/native/java/net/NetworkInterface_winXP.c
--- a/src/windows/native/java/net/NetworkInterface_winXP.c    Mon Jun 27 
13:21:34 2011 -0700
+++ b/src/windows/native/java/net/NetworkInterface_winXP.c    Mon Aug 29 
17:02:56 2011 +0800
@@ -194,8 +194,7 @@
      while (curr != NULL) {
          netaddr *netaddrP;
          ret = enumAddresses_win(env, curr, &netaddrP);
-        if ((*env)->ExceptionOccurred(env)) {
-            free_netaddr(netaddrP);
+        if (ret == -1) {
              return -1;
          }
          curr->addrs = netaddrP;
@@ -449,8 +448,7 @@
       */
      if (netaddrCount < 0) {
          netaddrCount = enumAddresses_win(env, ifs, &netaddrP);
-        if ((*env)->ExceptionOccurred(env)) {
-            free_netaddr(netaddrP);
+        if (count == -1) {
              return NULL;
          }
      }

And from my point of view, such scenario may also appear in other parts, 
maybe a more thorough check is needed for all modules.

Regards!
- Jonathan Lu

On 08/29/2011 04:40 PM, Michael McMahon wrote:
> Jonathan,
>
> I think the change looks reasonable. But, we should make the equivalent
> change at the other site where enumAddresses_win() is called in the 
> same file.
>
> - Michael.
>
> On 29/08/11 09:14, Jonathan Lu wrote:
>> Hello everybody,
>>
>> I got one crash issue on OpenJDK7 windows build.
>>
>> I captured the stack trace of such a crash, which happens 
>> intermittently on my 64bit Windows 2008 server. But unfortunately I 
>> have no simple test case to reproduce this problem.
>>
>> RtlInterlockedFlushSList+0x2ea (0x779F2A7F [ntdll+0x32a7f])
>> RtlInterlockedFlushSList+0x572 (0x779F2D07 [ntdll+0x32d07])
>> RtlInterlockedFlushSList+0x45d (0x779F2BF2 [ntdll+0x32bf2])
>> HeapFree+0x14 (0x755A14D1 [kernel32+0x114d1])
>> free+0x1c (0x7284016A [msvcr100+0x1016a])
>> free_netaddr+0x11 (networkinterface.c:107, 0x725A12AC [net+0x12ac])
>> getAllInterfacesAndAddresses+0xb6 (networkinterface_winxp.c:199, 
>> 0x725AB4C8 [net+0xb4c8])
>> Java_java_net_NetworkInterface_getAll_XP+0x12 
>> (networkinterface_winxp.c:693, 0x725AB7AB [net+0xb7ab])
>>
>> From the code at 
>> src/windows/native/java/net/NetworkInterface_winXP.c:195, I believe 
>> it is the dangling pointers that caused this problem. The 
>> uninitialized pointer netaddrP is exceptionally freed if the call to 
>> Windows API "GetIpAddrTable()" fails.
>>
>> So here's one proposed solution for this issue, can anybody please 
>> help to take a look?
>>
>> diff -r 9b8c96f96a0f 
>> src/windows/native/java/net/NetworkInterface_winXP.c
>> --- a/src/windows/native/java/net/NetworkInterface_winXP.c    Mon Jun 
>> 27 13:21:34 2011 -0700
>> +++ b/src/windows/native/java/net/NetworkInterface_winXP.c    Mon Aug 
>> 29 14:59:09 2011 +0800
>> @@ -194,8 +194,7 @@
>>      while (curr != NULL) {
>>          netaddr *netaddrP;
>>          ret = enumAddresses_win(env, curr, &netaddrP);
>> -        if ((*env)->ExceptionOccurred(env)) {
>> -            free_netaddr(netaddrP);
>> +        if (ret == -1) {
>>              return -1;
>>          }
>>          curr->addrs = netaddrP;
>>
>> Best regards!
>>
>>                                                                                                                                
>> Jonathan Lu
>>
>