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authorVasiliy Kulikov <segooon@gmail.com>2010-10-30 22:54:47 +0400
committerAndi Kleen <ak@linux.intel.com>2010-12-14 23:40:09 +0100
commitbe6eb177af13eceaef0052a0628b7153844bbea9 (patch)
treeef31a23809760dd0d6941c10fc5d65b55bf680bb /arch/x86
parente110ca176b8d6499d9b6d69a5e1b9055f10e6a1b (diff)
KVM: x86: fix information leak to userland
commit 97e69aa62f8b5d338d6cff49be09e37cc1262838 upstream. Structures kvm_vcpu_events, kvm_debugregs, kvm_pit_state2 and kvm_clock_data are copied to userland with some padding and reserved fields unitialized. It leads to leaking of contents of kernel stack memory. We have to initialize them to zero. In patch v1 Jan Kiszka suggested to fill reserved fields with zeros instead of memset'ting the whole struct. It makes sense as these fields are explicitly marked as padding. No more fields need zeroing. Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/x86.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ff274a142ed..eee5cdd29bc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2220,6 +2220,7 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
!kvm_exception_is_soft(vcpu->arch.exception.nr);
events->exception.nr = vcpu->arch.exception.nr;
events->exception.has_error_code = vcpu->arch.exception.has_error_code;
+ events->exception.pad = 0;
events->exception.error_code = vcpu->arch.exception.error_code;
events->interrupt.injected =
@@ -2233,13 +2234,14 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
events->nmi.injected = vcpu->arch.nmi_injected;
events->nmi.pending = vcpu->arch.nmi_pending;
events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu);
+ events->nmi.pad = 0;
events->sipi_vector = vcpu->arch.sipi_vector;
events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
| KVM_VCPUEVENT_VALID_SIPI_VECTOR
| KVM_VCPUEVENT_VALID_SHADOW);
-
+ memset(&events->reserved, 0, sizeof(events->reserved));
vcpu_put(vcpu);
}
@@ -2289,6 +2291,7 @@ static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
dbgregs->dr6 = vcpu->arch.dr6;
dbgregs->dr7 = vcpu->arch.dr7;
dbgregs->flags = 0;
+ memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
vcpu_put(vcpu);
}
@@ -2756,6 +2759,7 @@ static int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
sizeof(ps->channels));
ps->flags = kvm->arch.vpit->pit_state.flags;
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
+ memset(&ps->reserved, 0, sizeof(ps->reserved));
return r;
}
@@ -3153,6 +3157,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
now_ns = timespec_to_ns(&now);
user_ns.clock = kvm->arch.kvmclock_offset + now_ns;
user_ns.flags = 0;
+ memset(&user_ns.pad, 0, sizeof(user_ns.pad));
r = -EFAULT;
if (copy_to_user(argp, &user_ns, sizeof(user_ns)))