Demi Marie Obenour writes: > On 7/15/26 14:54, Alyssa Ross wrote: >> Demi Marie Obenour writes: >> >>> On 7/13/26 05:04, Alyssa Ross wrote: >>>> Demi Marie Obenour writes: >>>> >>>>> This seems to be a fairly significant hole in the VMM's sandbox. >>>>> Various code operates in that directory and isn't secure against >>>>> symlink attacks. >>>>> >>>>> Does the VMM really need write access to that directory? Could it >>>>> be given access to a subdirectory that is mounted "nosymfollow"? >>>> >>>> I think it's just so it can create e.g. the serial file. That could >>>> indeed be moved to a subdirectory. The ideal solution is of course for >>>> Cloud Hypervisor to be able to accept every file it would otherwise >>>> create as an open file descriptor, which I expect will happen >>>> eventually. >>> >>> Should it be moved to a subdirectory for now? That would make the >>> sandbox meaningful in practice. >> >> I suppose it could be. Might make more sense to dedicate efforts >> towards fixing Cloud Hypervisor to accept file descriptors for the ~2 >> paths it currently needs to create, though. (That's obviously more >> work, but also more useful.) If we were to work around this in >> Spectrum, we could keep symlinks outside the directory pointing into it, >> to keep paths nice and avoid churn once we can put them back in the >> parent directory. > > Do you happen to know which paths these are? I think it might just be "serial"? Not sure.