Commit 9bafc34d authored Jul 16, 2021 by Nicholas Piggin Committed by Greg Kroah-Hartman Jul 28, 2021

KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak



[ Upstream commit bc4188a2f56e821ea057aca6bf444e138d06c252 ]

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: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210716024310.164448-2-npiggin@gmail.com


Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f5dfcd1d

arch/powerpc/kvm/powerpc.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1995,9 +1995,9 @@ 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;
		@@ -2021,9 +2021,9 @@ 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;