Xen: properly bound buffer access when parsing cpu/*/availability

At the same time reduce the local buffers to 16 bytes each.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index 4dcfced..084041d 100644 (file)
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -25,10 +25,10 @@ static void disable_hotplug_cpu(int cpu)
 static int vcpu_online(unsigned int cpu)
 {
        int err;
-       char dir[32], state[32];
+       char dir[16], state[16];
 
        sprintf(dir, "cpu/%u", cpu);
-       err = xenbus_scanf(XBT_NIL, dir, "availability", "%s", state);
+       err = xenbus_scanf(XBT_NIL, dir, "availability", "%15s", state);
        if (err != 1) {
                if (!xen_initial_domain())
                        printk(KERN_ERR "XENBUS: Unable to read cpu state\n");