tree 700215bc94e83bb7f31e0ef3f9f6a59183257bec
parent cfa39381173d5f969daf43582c95ad679189cbc9
author Paolo Bonzini <pbonzini@redhat.com> 1548783676 +0100
committer Paolo Bonzini <pbonzini@redhat.com> 1549562576 +0100

KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)

Bugzilla: 1671930

Emulation of certain instructions (VMXON, VMCLEAR, VMPTRLD, VMWRITE with
memory operand, INVEPT, INVVPID) can incorrectly inject a page fault
when passed an operand that points to an MMIO address.  The page fault
will use uninitialized kernel stack memory as the CR2 and error code.

The right behavior would be to abort the VM with a KVM_EXIT_INTERNAL_ERROR
exit to userspace; however, it is not an easy fix, so for now just
ensure that the error code and CR2 are zero.

Embargoed until Feb 7th 2019.

Reported-by: Felix Wilhelm <fwilhelm@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>