Avoid a crash if the guest combines FW_CFG_WRITE_CHANNEL with a wrong value.
Signed-off-by: Blue Swirl <blauwir...@gmail.com> --- hw/fw_cfg.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/hw/fw_cfg.c b/hw/fw_cfg.c index 663ad80..8df265c 100644 --- a/hw/fw_cfg.c +++ b/hw/fw_cfg.c @@ -214,7 +214,8 @@ static void fw_cfg_write(FWCfgState *s, uint8_t value) 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->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); -- 1.6.2.4