Description

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12 svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB. However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and clearing clean bits in vmcb12 is not architecturally defined. Move vmcb_mark_dirty() to callers and drop it for vmcb12. This also facilitates incoming refactoring that does not pass the entire VMCB to svm_copy_lbrs().

References 3

• git.kernel.org https://git.kernel.org/stable/c/9efe23568806d1cd06f7d146f9b3037b8d585a9f
• git.kernel.org https://git.kernel.org/stable/c/a3f0981a5a0e0bd51ad74cc7d9eed32294b24002
• git.kernel.org https://git.kernel.org/stable/c/b53ab5167a81537777ac780bbd93d32613aa3bda

Remediation