From e14ef1095387f764d95614d3ec9e4d07c82a3533 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 16 Jul 2021 12:43:10 +1000 Subject: [PATCH] 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: b3cebfe8c1ca ("KVM: PPC: Move vcpu_load/vcpu_put down to each ioctl case in kvm_arch_vcpu_ioctl") Reported-by: Alexey Kardashevskiy Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210716024310.164448-2-npiggin@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/kvm/powerpc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 32fa0fa3d4ff5..543db9157f3b1 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -2041,9 +2041,9 @@ 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; @@ -2067,9 +2067,9 @@ 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;