In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: nv: Re-translate VNCR before injecting abort
KVM faults in the VNCR page with FOLL_WRITE whenever the guest aborts
for a write, similar to how a regular stage-2 mapping is handled. It is
entirely possible that the guest reads from the VNCR before writing to
it, in which case the PFN could only be read-only. Invalidate the VNCR TLB and re-fetch the translation upon taking a VNCR
abort, allowing the host mapping to be faulted in for write the second
time around.
Interestingly enough, this also satisfies the ordering requirements of FEAT_ETS2/3 between descriptor updates and MMU faults.
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
References 3
https://git.kernel.org/stable/c/0a5dd8cf4d58ea28da132c2097cd1c525302ac48
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/bb645aa0a4caeaf7f9cd32e9a948594d434c1a8f
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/ea7a76d7d614b5f82b4d0785f9af3550e860a71a
416baaa9-dc9f-4396-8d5f-8c081fb06d67