ALSA: usb-audio: Kill timer properly at removal

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Kill timer properly at removal The USB-audio MIDI code initializes the timer, but in a rare case, the driver might be freed without the disconnect call. This leaves the timer in an active state while the assigned object is released via snd_usbmidi_free(), which ends up with a kernel warning when the debug configuration is enabled, as spotted by fuzzer. For avoiding the problem, put timer_shutdown_sync() at snd_usbmidi_free(), so that the timer can be killed properly. While we're at it, replace the existing timer_delete_sync() at the disconnect callback with timer_shutdown_sync(), too.

References

• https://git.kernel.org/stable/c/06513dd6d32c37d0364db8488cfdf3e14da238a8
• https://git.kernel.org/stable/c/efaf61052b8ff9ee8968912fbaf02c2847c78ede
• https://git.kernel.org/stable/c/647410a7da46067953a53c0d03f8680eff570959
• https://git.kernel.org/stable/c/c611b9e55174e439dcd85a72969b43a95f3827a4
• https://git.kernel.org/stable/c/62066758d2ae169278e5d6aea5995b1b6f6ddeb5
• https://git.kernel.org/stable/c/0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1