From 5488499f9c645d6c1ffe151be196df38ee5a56b4 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Oct 2024 11:23:23 -0700 Subject: KVM: Explicitly initialize all fields at the start of kvm_vcpu_map() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Explicitly initialize the entire kvm_host_map structure when mapping a pfn, as some callers declare their struct on the stack, i.e. don't zero-initialize the struct, which makes the map->hva in kvm_vcpu_unmap() *very* suspect. Tested-by: Alex Bennée Signed-off-by: Sean Christopherson Tested-by: Dmitry Osipenko Signed-off-by: Paolo Bonzini Message-ID: <20241010182427.1434605-22-seanjc@google.com> --- virt/kvm/kvm_main.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 90e2a1f1de60..4074f49eb3f1 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3061,32 +3061,24 @@ void kvm_release_pfn(kvm_pfn_t pfn, bool dirty) int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) { - kvm_pfn_t pfn; - void *hva = NULL; - struct page *page = KVM_UNMAPPED_PAGE; + map->page = KVM_UNMAPPED_PAGE; + map->hva = NULL; + map->gfn = gfn; - pfn = gfn_to_pfn(vcpu->kvm, gfn); - if (is_error_noslot_pfn(pfn)) + map->pfn = gfn_to_pfn(vcpu->kvm, gfn); + if (is_error_noslot_pfn(map->pfn)) return -EINVAL; - if (pfn_valid(pfn)) { - page = pfn_to_page(pfn); - hva = kmap(page); + if (pfn_valid(map->pfn)) { + map->page = pfn_to_page(map->pfn); + map->hva = kmap(map->page); #ifdef CONFIG_HAS_IOMEM } else { - hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB); + map->hva = memremap(pfn_to_hpa(map->pfn), PAGE_SIZE, MEMREMAP_WB); #endif } - if (!hva) - return -EFAULT; - - map->page = page; - map->hva = hva; - map->pfn = pfn; - map->gfn = gfn; - - return 0; + return map->hva ? 0 : -EFAULT; } EXPORT_SYMBOL_GPL(kvm_vcpu_map); -- cgit v1.2.3-70-g09d2