Affected: Linux

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

usb: gadget: f_uac1_legacy: remove broken string configfs attributes

The UAC1_STR_ATTRIBUTE macro defines configfs show/store handlers for the fn_play, fn_cap, and fn_cntl string options. The store function contains an inverted null check on the kstrndup() return value.

This means every write attempt returns -ENOMEM on success and dereferences a NULL pointer on allocation failure. The attributes have been broken and unused for many years.

Remove the UAC1_STR_ATTRIBUTE macro and the three attributes it generated. The internal defaults (FILE_PCM_PLAYBACK, FILE_PCM_CAPTURE, FILE_CONTROL) set in f_audio_alloc_inst() are unaffected.