tree a1754859d4783dd92faf2da6c221bd941fcb6f5b
parent 456fd889227fd52e70e6aa8d127cdf92a347fec8
author Maxim Levitsky <mlevitsk@redhat.com> 1626303384 +0300
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1629269824 +0200

KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653)

commit 0f923e07124df069ba68d8bb12324398f4b6b709 upstream.

* Invert the mask of bits that we pick from L2 in
  nested_vmcb02_prepare_control

* Invert and explicitly use VIRQ related bits bitmask in svm_clear_vintr

This fixes a security issue that allowed a malicious L1 to run L2 with
AVIC enabled, which allowed the L2 to exploit the uninitialized and enabled
AVIC to read/write the host physical memory at some offsets.

Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>