crash from midi device

[Justin Sherrill]

Tse, do you want me to set you up with a bugs account, and do you want
it to be associated with 1 at tse.gratis?

On Wed, Jun 5, 2019 at 9:01 PM Tse <1 at tse.gratis> wrote:
>
> I was having trouble getting an account to submit a bug report
>
> So here's a bug fix instead!!
>
> The original bug was a repeatable crash when plugging in usb midi device:
> uaudio0: <vendor 0x16c0 MIDI EXpression BLUE, class 0/0, rev 2.00/1.03, addr 1> on usbus0
> panic: trying to free NULL pointer
> cpuid = 1
> Trace beginning at frame 0xfffff801eb967810
> kfree() at kfree+0x5b0 0xffffffff8058e900
> kfree() at kfree+0x5b0 0xffffffff8058e900
> uaudio_attach() at uaudio_attach+0x1b5 0xffffffff862040a5
> device_doattach() at device_doattach+0x369 0xffffffff805bd2a9
> usb_probe_and_attach() at usb_probe_and_attach+0x176 0xffffffff809091a6
> uhub_explore() at uhub_explore+0x221 0xffffffff8090ffa1
> Debugger("panic")
>
> --- a/sys/bus/u4b/audio/uaudio.c
> +++ b/sys/bus/u4b/audio/uaudio.c
> @@ -4871,7 +4871,7 @@ uaudio_mixer_fill_info(struct uaudio_softc *sc,
>
>         if (desc == NULL) {
>                 DPRINTF("no Audio Control header\n");
> -               goto done;
> +               return;
>         }
>         acdp = desc;
>
> @@ -4879,7 +4879,7 @@ uaudio_mixer_fill_info(struct uaudio_softc *sc,
>             (acdp->bDescriptorType != UDESC_CS_INTERFACE) ||
>             (acdp->bDescriptorSubtype != UDESCSUB_AC_HEADER)) {
>                 DPRINTF("invalid Audio Control header\n");
> -               goto done;
> +               return;
>         }
>         /* "wTotalLen" is allowed to be corrupt */
>         wTotalLen = UGETW(acdp->wTotalLength) - acdp->bLength;
> @@ -4895,7 +4895,7 @@ uaudio_mixer_fill_info(struct uaudio_softc *sc,
>
>         if (iot == NULL) {
>                 DPRINTF("no memory!\n");
> -               goto done;
> +               return;
>         }
>         while ((desc = usb_desc_foreach(cd, desc))) {