From dc9ce71e66b84497c375c529d818d8e8d0d793a9 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 9 Jan 2020 15:56:20 -0800 Subject: KVM: Return immediately if __kvm_gfn_to_hva_cache_init() fails Check the result of __kvm_gfn_to_hva_cache_init() and return immediately instead of relying on the kvm_is_error_hva() check to detect errors so that it's abundantly clear KVM intends to immediately bail on an error. Note, the hva check is still mandatory to handle errors on subqeuesnt calls with the same generation. Similarly, always return -EFAULT on error so that multiple (bad) calls for a given generation will get the same result, e.g. on an illegal gfn wrap, propagating the return from __kvm_gfn_to_hva_cache_init() would cause the initial call to return -EINVAL and subsequent calls to return -EFAULT. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7fa56ccdbe50..ffec9f427b55 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2180,8 +2180,10 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, BUG_ON(len + offset > ghc->len); - if (slots->generation != ghc->generation) - __kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len); + if (slots->generation != ghc->generation) { + if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) + return -EFAULT; + } if (kvm_is_error_hva(ghc->hva)) return -EFAULT; @@ -2213,8 +2215,10 @@ int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, BUG_ON(len > ghc->len); - if (slots->generation != ghc->generation) - __kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len); + if (slots->generation != ghc->generation) { + if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) + return -EFAULT; + } if (kvm_is_error_hva(ghc->hva)) return -EFAULT; -- cgit v1.2.3-59-g8ed1b