[libvirt] [PATCH] qemu: add pointer check in qemuMonitorLastError

[Daniel Henrique Barboza]

On 9/19/19 5:01 AM, Xu Yandong wrote:
> We found a exception when libvirt occurrs segmentation fault.
> thread 1 is waiting object lock in qemuConnectMonitor,
> qemu process exits and sends EOF event as well, so thread 2 invokes
> qemuMonitorLastError but pointer mon is NULL.
>
> Signed-off-by: Xu Yandong <xuyandong2 at huawei.com>
> ---

Reviewed-by: Daniel Henrique Barboza <danielhb413 at gmail.com>

>   src/qemu/qemu_monitor.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
> index aa230b3306..28f18391a5 100644
> --- a/src/qemu/qemu_monitor.c
> +++ b/src/qemu/qemu_monitor.c
> @@ -1103,7 +1103,7 @@ qemuMonitorSend(qemuMonitorPtr mon,
>   virErrorPtr
>   qemuMonitorLastError(qemuMonitorPtr mon)
>   {
> -    if (mon->lastError.code == VIR_ERR_OK)
> +    if (!mon || mon->lastError.code == VIR_ERR_OK)
>           return NULL;
>   
>       return virErrorCopyNew(&mon->lastError);