What happened
In the Linux kernel, the following vulnerability has been resolved: nvdimm: pmem: keep PREFLUSH before data writes pmem_submit_bio() records a REQ_PREFLUSH error, but continues to copy the bio data and can later overwrite the error with a successful REQ_FUA flush. That lets data writes run after a failed preflush and can complete the bio successfully despite the failed ordering barrier. Run the REQ_PREFLUSH flush synchronously before touching the bio data and complete the bio with the flush error if it fails. Keep asynchronous flush chaining for REQ_FUA. At that point, data copy has completed and the parent bio can wait for the chained flush bio.
Affected versions
Linux: c5d4355d10d414a96ca870b731756b89d068d57a through before 770a90c2127220f0fc194ce909ad4f0842e141cb (git); c5d4355d10d414a96ca870b731756b89d068d57a through before 72561ca1ab96f0f0f32737a6171641e05a318538 (git); c5d4355d10d414a96ca870b731756b89d068d57a through before c644a2f8fef5618fcf453c591177700fd07dd024 (git); 5.3 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.