Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state Explicitly flush caches after intra-host migration before clearing "SEV active" on the source VM, as doing cache maintenance afterwards creates a tiny window where memory reclaim could return memory to the host without performing a cache flush, e.g. as pointed out by Sashiko: CPU1 in sev_migrate_from(): src->active = false; CPU2 running concurrent unmap: Since active is false, the automatic cache flush in sev_guest_memory_reclaimed is skipped. The host frees and reallocates the page. CPU1 in sev_migrate_from(): sev_writeback_caches(src_kvm); Executes a hardware cache flush (wbnoinvd), which writes the guest's old dirty ciphertext over the new page owner's data.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 37dfb676fafd1eef36fe0bb649607afbb0d5521b before 8b7d4f68fef96cebe0b6dbb6e5607772337f7369; affected d4cc2dff12116a700add601c0262132cc26e1b2c before de83ff6a4d8f3618473bedb3c4400020c22e8a8a; affected 93de2a6a4b91b72607136dd656edf03fb399d27f before 973ea70393e885e540f714904e51bc6cac80e3d7 |
| Linux / Linux | affected 6.18.55 before 6.18.56; affected 7.2.9 before 7.2.10 |
CWE
No CWE identifiers supplied.