> > > >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. Miklos - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
