CVE-2023-53996
CriticalCVSS 9.3Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
In the Linux kernel, the enc_dec_hypercall() function was changed to accept a size instead of a page count. The previous version forced rounding up, causing pages to be incorrectly marked as decrypted during live migration, leading to consistent data corruption.
Risk Assessment
Risk of data corruption during live migration of virtual machines using AMD SEV, potentially compromising data integrity.
Recommendation
Install Linux kernel updates containing this fix. Ensure the system is updated before performing live migrations.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: x86/sev: Make enc_dec_hypercall() accept a size instead of npages enc_dec_hypercall() accepted a page count instead of a size, which forced its callers to round up. As a result, non-page aligned vaddrs caused pages to be spuriously marked as decrypted via the encryption status hypercall, which in turn caused consistent corruption of pages during live migration. Live migration requires accurate encryption status information to avoid migrating pages from the wrong perspective.