CVE-2024-26990
May 01, 2024
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
Check kvm_mmu_page_ad_need_write_protect() when deciding whether to
write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU
accounts for any role-specific reasons for disabling D-bit dirty logging.
Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is
being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled.
KVM always disables PML when running L2, even when L1 and L2 GPAs are in
the some domain, so failing to write-protect TDP MMU SPTEs will cause
writes made by L2 to not be reflected in the dirty log.
[sean: massage shortlog and changelog, tweak ternary op formatting]
Related Resources (9)
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Contact UsCVSS v4
Base Score:
6.8
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.5
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
EPSS
Base Score:
0.01