diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-10-13 21:12:30 +0000 |
|---|---|---|
| committer | David Woodhouse <dwmw@amazon.co.uk> | 2022-11-30 19:25:24 +0000 |
| commit | 5762cb10235776dd1ed5f5f9d6c1aff2b73bec5c (patch) | |
| tree | d4343c8d4b0f9f0c2dee39fef22166ef1aa95a51 /virt | |
| parent | 9f87791d686d85614584438d4f249eb32ef7964c (diff) | |
| download | lwn-5762cb10235776dd1ed5f5f9d6c1aff2b73bec5c.tar.gz lwn-5762cb10235776dd1ed5f5f9d6c1aff2b73bec5c.zip | |
KVM: Do not partially reinitialize gfn=>pfn cache during activation
Don't partially reinitialize a gfn=>pfn cache when activating the cache,
and instead assert that the cache is not valid during activation. Bug
the VM if the assertion fails, as use-after-free and/or data corruption
is all but guaranteed if KVM ends up with a valid-but-inactive cache.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/pfncache.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index 5b2512793691..c1a772cedc4b 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -345,6 +345,8 @@ void kvm_gpc_init(struct gfn_to_pfn_cache *gpc, struct kvm *kvm, gpc->kvm = kvm; gpc->vcpu = vcpu; gpc->usage = usage; + gpc->pfn = KVM_PFN_ERR_FAULT; + gpc->uhva = KVM_HVA_ERR_BAD; } EXPORT_SYMBOL_GPL(kvm_gpc_init); @@ -353,10 +355,8 @@ int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len) struct kvm *kvm = gpc->kvm; if (!gpc->active) { - gpc->khva = NULL; - gpc->pfn = KVM_PFN_ERR_FAULT; - gpc->uhva = KVM_HVA_ERR_BAD; - gpc->valid = false; + if (KVM_BUG_ON(gpc->valid, kvm)) + return -EIO; spin_lock(&kvm->gpc_lock); list_add(&gpc->list, &kvm->gpc_list); |