823021 - Remove hard coded windows dll paths from WMFUtils.cpp

Status: RESOLVED DUPLICATE of bug 823924

(Core :: Audio/Video, defect)

Description

[Jim Mathies [:jimm]]

http://mxr.mozilla.org/mozilla-central/source/content/media/wmf/WMFUtils.cpp#213

Presumably what ehsan meant in bug 799315 was to dynamically get the location of these dlls.

Not sure if we even need to do that since I think the system dll loader protects most system dlls (like user32, etc..) from getting hijacked. I'd guess these wmf dlls get the same treatment.

Either way the hard coded paths to "c:\windows" have got to go.

Comment 1

[Masatoshi Kimura [:emk]]

WinXP systems woldn't know about mf DLLs.
That said, I also think we don't need the full path here because all supported systems have SetDllDirectory now.

Comment 2

[Jim Mathies [:jimm]]

(In reply to Masatoshi Kimura [:emk] from comment #1)
> WinXP systems woldn't know about mf DLLs.
> That said, I also think we don't need the full path here because all
> supported systems have SetDllDirectory now.

So if this wmf code won't work on xp due to missing dlls, we should be doing a simple os version check. I hope we're not relying on a failed dll load to detect support if we already know support isn't there.

Comment 3

[Masatoshi Kimura [:emk]]

(In reply to Jim Mathies [:jimm] from comment #2)
> So if this wmf code won't work on xp due to missing dlls, we should be doing
> a simple os version check.
The version check is already present.
https://hg.mozilla.org/mozilla-central/rev/a75e9af08e9c#l17.94

> I hope we're not relying on a failed dll load to
> detect support if we already know support isn't there.
We removed such a reliance as a part of preventing DLL hijacking attack.

Comment 4

[Chris Pearce [:cpearce (Not reading bugmail)]]

Yeah, what emk said.

I'm going on holiday for three weeks, so I'll deal with this when I get back, unless some enthusiastic person wants it handled before that.

Comment 5

[Paul Adenot (:padenot)]

Duping against bug 823924, since it has the patch we are discussing here (i.e. removing the absolute path).