Revert "KVM: x86: work around leak of uninitialized stack contents" (25597f64) · Commits · 戴 / test

handle_vmptrst()/handle_vmread() stopped injecting #PF unconditionally and switched to nested_vmx_handle_memory_failure() which just kills the guest with KVM_EXIT_INTERNAL_ERROR in case of MMIO access, zeroing 'exception' in kvm_write_guest_virt_system() is not needed anymore. This reverts commit . Signed-off-by:

Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200605115906.532682-2-vkuznets@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

+0 −7

Original line number	Diff line number	Diff line
		@@ -5647,13 +5647,6 @@ int kvm_write_guest_virt_system(struct kvm_vcpu vcpu, gva_t addr, void val,
		/* kvm_write_guest_virt_system can pull in tons of pages. */
		vcpu->arch.l1tf_flush_l1d = true;

		/*
		* FIXME: this should call handle_emulation_failure if X86EMUL_IO_NEEDED
		* is returned, but our callers are not ready for that and they blindly
		* call kvm_inject_page_fault. Ensure that they at least do not leak
		* uninitialized kernel stack memory into cr2 and error code.
		*/
		memset(exception, 0, sizeof(*exception));
		return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
		PFERR_WRITE_MASK, exception);
		}

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