CVE-2026-31701ALSA: caiaq: take a reference on the USB device in create_card()

Official description

In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: take a reference on the USB device in create_card() The caiaq driver stores a pointer to the parent USB device in cdev->chip.dev but never takes a reference on it. The card's private_free callback, snd_usb_caiaq_card_free(), can run asynchronously via snd_card_free_when_closed() after the USB device has already been disconnected and freed, so any access to cdev->chip.dev in that path dereferences a freed usb_device. On top of the refcounting issue, the current card_free implementation calls usb_reset_device(cdev->chip.dev). A reset in a free callback is inappropriate: the device is going away, the call takes the device lock in a teardown context, and the reset races with the disconnect path that the callback is already cleaning up after. Take a reference on the USB device in create_card() with usb_get_dev(), drop it with usb_put_dev() in the free callback, and remove the usb_reset_device() call.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/493b3a682ededc804555755f5d2193201339612d
• https://git.kernel.org/stable/c/dbcf7588e8dea017ddb3f18ec2766f7d2e5f2a0e
• https://git.kernel.org/stable/c/ac7345f68cda6989016d85d63f7b244c064aa8f6
• https://git.kernel.org/stable/c/f6634af5de728a46792f674a66d7843570cb68f7
• https://git.kernel.org/stable/c/1d9be95aee6c6246a21752e60c9519902649f482
• https://git.kernel.org/stable/c/6473ed16df1fe88051140611b3eb9a49be7f429e
• https://git.kernel.org/stable/c/59b622a043cffc58b7638cd85ae6c30a0904f8e6
• https://git.kernel.org/stable/c/80bb50e2d459213cccff3111d5ef98ed4238c0d5