Binary package hint: nspluginwrapper
There is a bug in the NPN_GetStringIdentifiers implementation in nspluginwrapper that makes it completely broken, 100% of the time. The bug exists in versions 1.2.0 and later. The issue is that NPIdentifiers are passed to the do_send_NPIdentifier function by _value_, not by pointer, which is how other parameters are passed to their marshallers. This is fine when calling rpc_method_send_reply (as in the singular version, NPN_GetStringIdentifier), but it results in a bug when marshalling arrays of NPIdentifiers, because the array marshalling code in rpc_message_send_args passes the individual elements by passing a pointer to their position in the array. This resulted in do_send_NPIdentifier interpreting the address of the NPIdentifier as the NPIdentifier itself. As a result, nspluginwrapper's implementation of NPN_GetStringIdentifiers was broken, because the NPIdentifier values that it returned to the plugin were mapped to garbage addresses in the browser.
My fix is to change NPIdentifiers to be passed by pointer. I sent the patch to upstream a while ago, but the author hasn't responded and there hasn't been any activity on the upstream nspluginwrapper source control system in a while. But I figure you'd probably like to incorporate it into Ubuntu.
Note that the patch has already been incorporated into Fedora. You can get more info about it here: https://bugzilla.redhat.com/show_bug.cgi?id=511897.
Created attachment 353833
patch
Description of problem (by Tristan Schmelcher):
Hello,
I'm a developer on Google's open-source O3D plugin project for doing
hardware-
http://
Google's V8 JavaScript JIT engine, so I've been working on compatibility
with nspluginwrapper so that we can support 64-bit Linux. Along the way I
discovered that one of the issues was a bug in nspluginwrapper's marshalling
of arrays of NPIdentifiers. A patch with the fix is attached. Apply with
"patch -p0 < FILENAME".
The bug exists in versions 1.2.0 and later. The issue is that NPIdentifiers
are passed to the do_send_
which is how other parameters are passed to their marshallers. This is fine
when calling rpc_method_
arrays of NPIdentifiers, because the array marshalling code in
rpc_message_
their position in the array. This resulted in do_send_
interpreting the address of the NPIdentifier as the NPIdentifier itself. As
a result, nspluginwrapper's implementation of NPN_GetStringId
broken, because the NPIdentifier values that it returned to the plugin were
mapped to garbage addresses in the browser.
My fix is to change NPIdentifiers to be passed by pointer. With this fix,
nspluginwrapper can successfully run O3D plugins built from our SVN trunk at
revision 19440 or later.
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