RFR: JDK-8007607

[John Zavgren]

Thanks, Dmitry.

If I were to rewrite the native code to throw exceptions, in the areas I indicated, and no one caught them, would that create any problems. I have the code in my sandbox right now for throwing them. If I can retain that in a graceful way, that seems like a prudent thing to do, if there are no negative consequences.

John


----- Original Message -----
From: dmitry.samersoff at oracle.com
To: john.zavgren at oracle.com
Cc: security-dev at openjdk.java.net
Sent: Tuesday, February 12, 2013 11:04:28 AM GMT -05:00 US/Canada Eastern
Subject: Re: RFR: JDK-8007607

John,

Changing everything for throw OOM is the right goal but it's a huge work
to do - it's meaningless to throw OOM if all callers doesn't check for
exception.

I'm in doubt it could be done all at once and probably this problem
should go to the huge TODO pile.

So I'm speaking about *one particular case*, where returned value could
lead to misinterpretation of security context and lead to security
vulnerability or subtle bug.

We have to throw OOM there and change all callers as well for this case.

-Dmitry

On 2013-02-12 19:51, John Zavgren wrote:
> On 02/08/2013 01:34 PM, Dmitry Samersoff wrote:
>> John,
>>
>>> Ideas?
>> It's a JNI so just throw OOM.
>>
>> -Dmitry
>>
>>
>> On 2013-02-08 21:38, John Zavgren wrote:
>>> Although I agree that the name: "GSS_C_NO_CHANNEL_BINDINGS" is
>>> misleading,
>>> I can't identify anything else that seems more appropriate.
>>>
>>> The header file:
>>> /jdk8-tl/jdk/src/share/native/sun/security/jgss/wrapper/gssapi.h defines
>>> GSS_C_NO_CHANNEL_BINDINGS as follows:
>>> #define GSS_C_NO_CHANNEL_BINDINGS ((gss_channel_bindings_t) 0)
>>>
>>> The symbol matches the prototype of the function:
>>>
>>>      */*
>>>       * Utility routine which creates a gss_channel_bindings_t structure
>>>       * using the specified org.ietf.jgss.ChannelBinding object.
>>>       */
>>>      gss_channel_bindings_t getGSSCB(JNIEnv *env, jobject jcb) {
>>>        gss_channel_bindings_t cb;
>>>        jobject jinetAddr;
>>>        jbyteArray value;
>>>
>>>        if (jcb == NULL) {
>>>          return GSS_C_NO_CHANNEL_BINDINGS;
>>>        }
>>>          cb = malloc(sizeof(struct gss_channel_bindings_struct));
>>>
>>>          if(cb == NULL)
>>>              return  GSS_C_NO_CHANNEL_BINDINGS;*
>>>
>>> There doesn't appear to be anything in our set of options that is more
>>> suggestive of a memory allocation failure and the symbol:
>>> GSS_C_NO_CHANNEL_BINDINGS seems to be logically correct.
>>>
>>> Ideas?
>>>
>>> On 02/06/2013 04:57 AM, Dmitry Samersoff wrote:
>>>> John,
>>>>
>>>> Not sure GSS_C_NO_CHANNEL_BINDINGS; is correct return value for this
>>>> case.
>>>>
>>>> I'm second to Valerie - it's better to throw OOM
>>>>
>>>> -Dmitry
>>>>
>>>>
>>>> On 2013-02-06 03:44, John Zavgren wrote:
>>>>> Greetings:
>>>>>
>>>>> I modified the native code to eliminate potential memory loss and
>>>>> crashes by checking the return values of malloc() and realloc() calls.
>>>>>
>>>>> The webrev image of these changes is visible at:
>>>>> http://cr.openjdk.java.net/~jzavgren/8007607/webrev.01/
>>>>>
>>>>> Thanks!
>>>>> John Zavgren
>>>>>
>>>
>>> -- 
>>> John Zavgren
>>> john.zavgren at oracle.com
>>> 603-821-0904
>>> US-Burlington-MA
>>>
>>
> When I change the procedures in the following files:
> 
> src/share/native/sun/security/jgss/wrapper/GSSLibStub.c
> src/share/native/sun/security/jgss/wrapper/NativeUtil.c
> src/share/native/sun/security/smartcardio/pcsc.c
> src/solaris/native/com/sun/security/auth/module/Solaris.c
> src/solaris/native/com/sun/security/auth/module/Unix.c
> 
> to fix inappropriate usages of malloc, realloc, etc. (e.g., not checking
> the return value and referring to a NULL pointer and crashing) should I
> modify every instance so that an OOM (Out Of Memory) exception is thrown
> (before returning) whenever memory allocation fails?
> 
> The exceptions would be thrown by a line of code that looks like:
> 
> throwOutOfMemoryError(JNIEnv *env, const char *msg);
> 
> where  throwOutOfMemoryError(...) wraps something like this:
> 
>             jclass cls = (*env)->FindClass(env, name);
> 
>                 if (cls != 0) /* Otherwise an exception has already been
> thrown */
>                                 (*env)->ThrowNew(env, cls, msg);
> 
> If this is the right idea, what messages should I pass when an OOM
> exception is thrown?
> 
> Thanks!
> John
> 


-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* Give Rabbit time, and he'll always get the answer