pc: Fix crash when attempting to hotplug CPU with negative ID

QMP command "{ 'execute': 'cpu-add', 'arguments': { 'id': -1 }}" may cause
QEMU SIGSEGV at:
 piix4_cpu_hotplug_req ()
    ...
    g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
    ...

Since for PC in current implementation id should be in range [0...maxcpus)
and maxcpus is already checked, add check for lower bound and error out
on incorrect value.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This commit is contained in:
Igor Mammedov 2013-05-30 17:09:34 +02:00 committed by Andreas Färber
parent 88f62c2b1d
commit 8de433cb08

View file

@ -927,6 +927,11 @@ void pc_hot_add_cpu(const int64_t id, Error **errp)
DeviceState *icc_bridge;
int64_t apic_id = x86_cpu_apic_id_from_index(id);
if (id < 0) {
error_setg(errp, "Invalid CPU id: %" PRIi64, id);
return;
}
if (cpu_exists(apic_id)) {
error_setg(errp, "Unable to add CPU: %" PRIi64
", it already exists", id);