KVM: x86: fix overlap between SPTE_MMIO_MASK and generation
The SPTE_MMIO_MASK overlaps with the bits used to track MMIO generation number. A high enough generation number would overwrite the SPTE_SPECIAL_MASK region and cause the MMIO SPTE to be misinterpreted. Likewise, setting bits 52 and 53 would also cause an incorrect generation number to be read from the PTE, though this was partially mitigated by the (useless if it weren't for the bug) removal of SPTE_SPECIAL_MASK from the spte in get_mmio_spte_generation. Drop that removal, and replace it with a compile-time assertion. Fixes: 6eeb4ef0 ("KVM: x86: assign two bits to track SPTE kinds") Reported-by:Ben Gardon <bgardon@google.com> Cc: stable@vger.kernel.org Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
parent
09cbcef6