Re: [Qemu-devel] [PATCH v2] hmp: Fix drive_add ... format=help crash

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 4/8/19 5:30 PM, Markus Armbruster wrote:
> drive_new() returns null without setting an error when it provided
> help.  add_init_drive() assumes null means failure, and crashes trying
> to report a null error.
> 
> Fixes: c4f26c9f37ce511e5fe629c21c180dc6eb7c5a25
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
> v2: Make tests/test-hmp.c cover the bug
> 
>  device-hotplug.c | 2 +-
>  tests/test-hmp.c | 1 +
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/device-hotplug.c b/device-hotplug.c
> index 6090d5f1e9..6153259d71 100644
> --- a/device-hotplug.c
> +++ b/device-hotplug.c
> @@ -48,7 +48,7 @@ static DriveInfo *add_init_drive(const char *optstr)
>  
>      mc = MACHINE_GET_CLASS(current_machine);
>      dinfo = drive_new(opts, mc->block_default_type, &err);
> -    if (!dinfo) {
> +    if (err) {
>          error_report_err(err);
>          qemu_opts_del(opts);
>          return NULL;
> diff --git a/tests/test-hmp.c b/tests/test-hmp.c
> index 8c49d2fdf1..54a01824dc 100644
> --- a/tests/test-hmp.c
> +++ b/tests/test-hmp.c
> @@ -31,6 +31,7 @@ static const char *hmp_cmds[] = {
>      "cpu 0",
>      "device_add ?",
>      "device_add usb-mouse,id=mouse1",
> +    "drive_add ignored format=help",
>      "mouse_button 7",
>      "mouse_move 10 10",
>      "mouse_button 0",
>