KVM: TDX: Fix a benign off-by-one bug on the end GPA for INIT_MEM_REGION

When verifying that the incoming GPA rage for INIT_MEM_REGION doesn't wrap,
check the inclusive last GPA, not the exclusive last GPA.  Super duper
technically, it's ok if the very last GPA is -1ull.  In practice, the flaw
is benign as KVM x86 disallows memslots with GPAs that exceed MAXPHYADDR,
i.e. INIT_MEM_REGION would fail with -EINVAL anyways due to the memslot
check in kvm_gmem_populate().

Opportunistically use check_add_overflow() instead of manually checking for
wrap, mostly so that the inclusive math doesn't need to be copy+pasted in
the "is private" check.

Fixes: c846b451d3c5 ("KVM: TDX: Add an ioctl to create initial guest memory")
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://patch.msgid.link/20260806170602.4112602-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

0 files changed, 0 insertions, 0 deletions