Affected: Linux

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

ALSA: usb-audio: Complete cleanup after system-resume errors

A failed system resume can leave the card unusable until reboot. usb_audio_resume() jumps to err_out when snd_usb_pcm_resume() or snd_usb_mixer_resume() fails. The error path skips the out: block, which restores D0 and decrements chip->num_suspended_intf.

The card stays in SNDRV_CTL_POWER_D3hot, so later control access blocks in snd_power_ref_and_wait(). USB core logs an interface resume callback error. It does not retry that callback, so a later callback cannot complete the skipped cleanup.

usb_audio_suspend() increments num_suspended_intf before returning success. A system-resume callback must consume the system-suspend count even if a component resume fails. Otherwise, the stranded count skews later suspend and resume cycles.

Do not apply this cleanup to runtime-resume errors. Runtime PM can retry -EAGAIN or -EBUSY without another suspend callback. The count must continue to describe that suspended interface. Other runtime-resume errors latch runtime_error in the PM core and do not cause an immediate callback retry.

Both parts of the system-resume error path are longstanding. Commit 88a8516a2128a ("ALSA: usbaudio: implement USB autosuspend") introduced err_out past the D0 restore. Commit 862b2509d157c ("ALSA: usb-audio: Fix inconsistent card PM state after resume") later moved num_suspended_intf-- into the out: block. The error path now sk…