Messages in this thread | | | Date | Wed, 18 Nov 2009 20:33:08 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH 0/2] vfs: ensure that dentries are revalidated on open (try #2) |
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Hi!
> > > Does it? Here's what I just did to check that: > > > > Yes it does, see http://seclists.org/bugtraq/2009/Oct/179 ... > > /proc does not allow you to use /proc/XX/fd of unrelated users; it is > > another mechanism disallowing access. (Plus, I did my experiments with > > /proc/XX/fd, not /exe).
> Thanks for the info. Took me a while to get through it but I read most > of the thread. I agree that it sounds like a very similar problem. > > I'm beginning to wonder whether the right answer is to just make > these /proc symlinks behave more like normal symlinks. Get rid of > LAST_BIND and have follow_link turn the dentry into a path via > d_path().
That would work for me.
> It's less efficient, but it means less special-casing in the path > walking code. I don't see /proc symlinks as being so performance > critical that we can't do it that way instead.
Current approach works with deleted files; without special-casing that will stop. But I see it as a good thing: you should not have to chmod 000 before deleting a file. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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