From 79593c086eb95eb2886f36ee6f78a1d6845e1bdf Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 29 Mar 2022 13:11:47 -0400 Subject: KVM: avoid double put_page with gfn-to-pfn cache If the cache's user host virtual address becomes invalid, there is still a path from kvm_gfn_to_pfn_cache_refresh() where __release_gpc() could release the pfn but the gpc->pfn field has not been overwritten with an error value. If this happens, kvm_gfn_to_pfn_cache_unmap will call put_page again on the same page. Cc: stable@vger.kernel.org Fixes: 982ed0de4753 ("KVM: Reinstate gfn_to_pfn_cache with invalidation support") Signed-off-by: David Woodhouse Signed-off-by: Paolo Bonzini --- virt/kvm/pfncache.c | 1 + 1 file changed, 1 insertion(+) (limited to 'virt') diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index ce878f4be4da..1621f8efd961 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -191,6 +191,7 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpc->uhva = gfn_to_hva_memslot(gpc->memslot, gfn); if (kvm_is_error_hva(gpc->uhva)) { + gpc->pfn = KVM_PFN_ERR_FAULT; ret = -EFAULT; goto out; } -- cgit