Messages in this thread | | | Subject | Re: fuse, get_user_pages, flush_anon_page, aliasing caches and all that again | From | Miklos Szeredi <> | Date | Thu, 21 Dec 2006 22:30:54 +0100 |
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> > > >The root of the problem is that copy_to_user() may cause page faults > >on the userspace buffer, and the page fault might (in case of a > >maliciously crafted filesystem) recurse into the filesystem itself. > > Would it be worthwhile to mlock the page? I know that needs root > privs or some capability, but a static buffer could be put aside when > fusermount is run.
And how would the kernel ensure, that the buffer supplied by userspace is mlocked and stays mlocked during the memory copy? I don't think that would simplify the kerel side much, and would complicate the userspace side considerably.
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