RFR: 8205342: windows : potential memleaks in getAdapter(s) in NetworkInterface_winXP.c

[Thomas Stüfe]

Hi Matthias,

thanks, good catch about the leak.

But could you not just simply free the error_msg_buf after the call to
JNU_ThrowByName?

JNU_ThrowByName copies the message string, so no need to keep it alive
afterwards:

diff -r e810abb27deb
src/java.base/windows/native/libnet/NetworkInterface_winXP.c
--- a/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
 Wed Jun 20 06:51:39 2018 +0200
+++ b/src/java.base/windows/native/libnet/NetworkInterface_winXP.c
 Wed Jun 20 10:21:57 2018 +0200
@@ -138,6 +138,7 @@
                     JNU_ThrowByName(env, "java/lang/Error",
                         "IP Helper Library GetAdaptersAddresses
function failure");
                 }
+                free(error_msg_buf);
             } else {
                 JNU_ThrowByName(env, "java/lang/Error",
                     "IP Helper Library GetAdaptersAddresses function failed");

Thanks, Thomas



On Wed, Jun 20, 2018 at 10:07 AM, Baesken, Matthias
<matthias.baesken at sap.com> wrote:
> Hello . Please review this small  fix that  fixes  potential  memory leaks
> in   getAdapter(s) in NetworkInterface_winXP.c  and simplifies the coding a
> bit too .
>
> Currently   when generating error messages ,   some memory  is malloc-ed
> for the error messages , but not always freed .
>
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> Bug:
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> https://bugs.openjdk.java.net/browse/JDK-8205342
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>
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> webrev :
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> http://cr.openjdk.java.net/~mbaesken/webrevs/8205342/
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> Thanks, Matthias
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