Backporting the sanity checks on pipes seems like a good idea. These are basically the same as Takashi Iwai's patches upstream. The difference is that upstream added two sanity checks to code that doesn't exist in 4.19.

I had talked about backporting fcc2cc1f3561 ("USB: move snd_usb_pipe_sanity_check into the USB core") but that's just a refactor and not a bug fix.

Hillf Danton (1): ALSA: usb-audio: Fix gpf in snd_usb_pipe_sanity_check

Takashi Iwai (1): ALSA: usb-audio: Sanity checks for each pipe and EP types

sound/usb/helper.c | 17 +++++++++++++++++ sound/usb/helper.h | 1 + sound/usb/quirks.c | 14 +++++++++++--- 3 files changed, 29 insertions(+), 3 deletions(-)