From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/2] Revert "KVM: x86: work around leak of uninitialized stack contents"
Date: Fri, 5 Jun 2020 13:59:06 +0200 [thread overview]
Message-ID: <20200605115906.532682-2-vkuznets@redhat.com> (raw)
In-Reply-To: <20200605115906.532682-1-vkuznets@redhat.com>
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 541ab2aeb28251bf7135c7961f3a6080eebcc705.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/x86.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9e41b5135340..0097a97d331f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -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);
}
--
2.25.4
next prev parent reply other threads:[~2020-06-05 11:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-05 11:59 [PATCH v2 1/2] KVM: nVMX: Properly handle kvm_read/write_guest_virt*() result Vitaly Kuznetsov
2020-06-05 11:59 ` Vitaly Kuznetsov [this message]
2020-06-05 17:33 ` [PATCH v2 2/2] Revert "KVM: x86: work around leak of uninitialized stack contents" Paolo Bonzini
2020-06-05 12:01 ` [PATCH v2 1/2] KVM: nVMX: Properly handle kvm_read/write_guest_virt*() result Vitaly Kuznetsov
2020-06-05 20:06 ` Sean Christopherson
2020-06-08 8:20 ` Vitaly Kuznetsov
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