On Tue, Oct 06, 2026 at 06:39:23PM +0900, 성병찬 wrote: > Yes, the backend causes the driver to corrupt its own virtqueue > free-list accounting. > > My concern was that, after privileged VDUSE setup, a delegated > unprivileged backend can trigger this by modifying a published > descriptor. However, my current reproducer demonstrates duplicate > descriptor allocation only. It does not demonstrate a host > memory-safety violation, cross-device impact, information disclosure, > or privilege escalation. > > I therefore agree that the current evidence supports a robustness > issue rather than a confirmed security vulnerability. > > Would a patch using the driver-owned desc_extra flags during detach > still be considered worthwhile, or is protection against this backend > behavior outside the intended threat model? > > Regards, > sungbyeongchan
It's outside a threat model but if the rest of data is coming from desc_extra I don't see a good reason to read flags from the descriptor. Will likely be better for cache, too.
