Commit bc4188a2 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak 



vcpu_put is not called if the user copy fails. This can result in preempt
notifier corruption and crashes, among other issues.

Fixes: b3cebfe8 ("KVM: PPC: Move vcpu_load/vcpu_put down to each ioctl case in kvm_arch_vcpu_ioctl")
Reported-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210716024310.164448-2-npiggin@gmail.com
parent bd31ecf4

arch/powerpc/kvm/powerpc.c

+2 −2
Original line number Diff line number Diff line
@@ -2048,9 +2048,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
	{

		struct kvm_enable_cap cap;

		r = -EFAULT;

		vcpu_load(vcpu);

		if (copy_from_user(&cap, argp, sizeof(cap)))

			goto out;

		vcpu_load(vcpu);

		r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);

		vcpu_put(vcpu);

		break;
@@ -2074,9 +2074,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
	case KVM_DIRTY_TLB: {

		struct kvm_dirty_tlb dirty;

		r = -EFAULT;

		vcpu_load(vcpu);

		if (copy_from_user(&dirty, argp, sizeof(dirty)))

			goto out;

		vcpu_load(vcpu);

		r = kvm_vcpu_ioctl_dirty_tlb(vcpu, &dirty);

		vcpu_put(vcpu);

		break;