1 files changed, 41 insertions, 0 deletions
diff --git a/freed-ora/tags/f18/3.8.6-201.fc18.gnu/0002-KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch b/freed-ora/tags/f18/3.8.6-201.fc18.gnu/0002-KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch
new file mode 100644
index 000000000..a4516e43e
--- /dev/null
+++ b/freed-ora/tags/f18/3.8.6-201.fc18.gnu/0002-KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch
@@ -0,0 +1,41 @@
+From c300aa64ddf57d9c5d9c898a64b36877345dd4a9 Mon Sep 17 00:00:00 2001
+From: Andy Honig <ahonig@google.com>
+Date: Mon, 11 Mar 2013 09:34:52 -0700
+Subject: [PATCH 2/3] KVM: x86: fix for buffer overflow in handling of
+ MSR_KVM_SYSTEM_TIME (CVE-2013-1796)
+
+If the guest sets the GPA of the time_page so that the request to update the
+time straddles a page then KVM will write onto an incorrect page.  The
+write is done byusing kmap atomic to get a pointer to the page for the time
+structure and then performing a memcpy to that page starting at an offset
+that the guest controls.  Well behaved guests always provide a 32-byte aligned
+address, however a malicious guest could use this to corrupt host kernel
+memory.
+
+Tested: Tested against kvmclock unit test.
+
+Signed-off-by: Andrew Honig <ahonig@google.com>
+Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
+---
+ arch/x86/kvm/x86.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
+index f7c850b..2ade60c 100644
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -1959,6 +1959,11 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+ 		/* ...but clean it before doing the actual write */
+ 		vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);
+ 
++		/* Check that the address is 32-byte aligned. */
++		if (vcpu->arch.time_offset &
++				(sizeof(struct pvclock_vcpu_time_info) - 1))
++			break;
++
+ 		vcpu->arch.time_page =
+ 				gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
+ 
+-- 
+1.8.1.4
+