--- xen-4.6.1/tools/qemu-xen-traditional/hw/fw_cfg.c.orig 2016-01-04 15:35:42.000000000 +0000
+++ xen-4.6.1/tools/qemu-xen-traditional/hw/fw_cfg.c 2016-03-06 16:42:33.464296362 +0000
@@ -54,11 +54,15 @@
static void fw_cfg_write(FWCfgState *s, uint8_t value)
{
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
- FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
+ FWCfgEntry *e = (s->cur_entry == FW_CFG_INVALID) ? NULL :
+ &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
FW_CFG_DPRINTF("write %d\n", value);
- if (s->cur_entry & FW_CFG_WRITE_CHANNEL && s->cur_offset < e->len) {
+ if (s->cur_entry & FW_CFG_WRITE_CHANNEL
+ && e != NULL
+ && e->callback
+ && s->cur_offset < e->len) {
e->data[s->cur_offset++] = value;
if (s->cur_offset == e->len) {
e->callback(e->callback_opaque, e->data);
@@ -88,7 +92,8 @@
static uint8_t fw_cfg_read(FWCfgState *s)
{
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
- FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
+ FWCfgEntry *e = (s->cur_entry == FW_CFG_INVALID) ? NULL :
+ &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
uint8_t ret;
if (s->cur_entry == FW_CFG_INVALID || !e->data || s->cur_offset >= e->len)