CVE-2024-56533

In the Linux kernel, the following vulnerability has been resolved:

ALSA: usx2y: Use sndcardfreewhenclosed() at disconnection

The USB disconnect callback is supposed to be short and not too-long waiting. OTOH, the current code uses sndcardfree() at disconnection, but this waits for the close of all used fds, hence it can take long. It eventually blocks the upper layer USB ioctls, which may trigger a soft lockup.

An easy workaround is to replace sndcardfree() with sndcardfreewhenclosed(). This variant returns immediately while the release of resources is done asynchronously by the card device release at the last close.