Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation Commit cc3ed80ae69f ("KVM: nSVM: always use vmcb01 to for vmsave/vmload of guest state") made KVM always use vmcb01 for the fields controlled by VMSAVE/VMLOAD, but it missed updating the VMLOAD/VMSAVE emulation code to always use vmcb01. As a result, if VMSAVE/VMLOAD is executed by an L2 guest and is not intercepted by L1, KVM will mistakenly use vmcb02. Always use vmcb01 instead of the current VMCB.

Affected versions

Linux: cc3ed80ae69f454c3d904af9f65394a540099723 through before 10063e1251c1485034a018236080792ad083dcc5 (git); cc3ed80ae69f454c3d904af9f65394a540099723 through before c3b7015000988ba35ecd5648f4b2283960f00543 (git); cc3ed80ae69f454c3d904af9f65394a540099723 through before 3880e331b0b31d0d5d3702b124f6c93539cd478a (git); cc3ed80ae69f454c3d904af9f65394a540099723 through before fce2fd4a2ca05670a91015aacccf96a1c26268fd (git); cc3ed80ae69f454c3d904af9f65394a540099723 through before d464cf1ed900d47c85393d40b00017b6adfc2e6c (git); cc3ed80ae69f454c3d904af9f65394a540099723 through before 0004ecb798b30e90d7ebfe74efae2d9423315a64 (git); cc3ed80ae69f454c3d904af9f65394a540099723 through before 127ccae2c185f62e6ecb4bf24f9cb307e9b9c619 (git); 5.13 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.