Pull sound fixes from Takashi Iwai:
"All fixes are small and for stable:
- a PCM ioctl race fix
- yet another USB-audio hardening for malicious descriptors
- Realtek ALC257 codec support"
* tag 'sound-4.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: pcm: prevent UAF in snd_pcm_info
ALSA: hda/realtek - New codec support for ALC257
ALSA: usb-audio: Add check return value for usb_string()
ALSA: usb-audio: Fix out-of-bound error
ALSA: seq: Remove spurious WARN_ON() at timer check