KVM: Forbid /dev/kvm being opened by a compat task when CONFIG_KVM_COMPAT=n
authorMarc Zyngier <maz@kernel.org>
Wed, 13 Nov 2019 16:05:23 +0000 (16:05 +0000)
committerPaolo Bonzini <pbonzini@redhat.com>
Wed, 13 Nov 2019 16:13:12 +0000 (17:13 +0100)
commitb9876e6de123adb52ac693bac08c493e989bd93e
treece6d3de7b302079d4b624276a18007a9118ba838
parent6cbee2b9eccfc1c93a03aaa286ec93331f7c95e7
KVM: Forbid /dev/kvm being opened by a compat task when CONFIG_KVM_COMPAT=n

On a system without KVM_COMPAT, we prevent IOCTLs from being issued
by a compat task. Although this prevents most silly things from
happening, it can still confuse a 32bit userspace that is able
to open the kvm device (the qemu test suite seems to be pretty
mad with this behaviour).

Take a more radical approach and return a -ENODEV to the compat
task.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
virt/kvm/kvm_main.c