CVE-2022-48793

In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: nSVM: fix potential NULL derefernce on nested migration

Turns out that due to review feedback and/or rebases I accidentally moved the call to nested_svm_load_cr3 to be too early, before the NPT is enabled, which is very wrong to do.

KVM cant even access guest memory at that point as nested NPT is needed for that, and of course it wont initialize the walk_mmu, which is main issue the patch was addressing.

Fix this for real.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/352193edda48e08e8824a7ece09aec830a603cfe
• https://git.kernel.org/stable/c/74b426bea4f7e3b081add2b88d4fba16d3af7ab6
• https://git.kernel.org/stable/c/e1779c2714c3023e4629825762bcbc43a3b943df