From: Igor Mammedov <imamm...@redhat.com> 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 <imamm...@redhat.com> Signed-off-by: Andreas Färber <afaer...@suse.de> --- hw/i386/pc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 4844a6b..553becb 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -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); -- 1.8.1.4