[PATCH] usb: gadget: f_uac1_legacy: cancel playback_work before freeing audio

[PATCH] usb: gadget: f_uac1_legacy: cancel playback_work before freeing audio

[Tristan Madani]

From: Tristan Madani <tristan@talencesecurity.com>

f_audio_free() frees the f_audio struct without first cancelling
playback_work. If the work function is still running or pending at the
time of the free, it will access freed memory via container_of.

Add cancel_work_sync() before cleanup and deallocation.

Fixes: c6994e6f067c ("USB: gadget: add USB Audio Gadget driver")
Cc: stable@vger.kernel.org
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
---
 drivers/usb/gadget/function/f_uac1_legacy.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/gadget/function/f_uac1_legacy.c b/drivers/usb/gadget/function/f_uac1_legacy.c
index 7c8d60c7e87d1..a9807697265c5 100644
--- a/drivers/usb/gadget/function/f_uac1_legacy.c
+++ b/drivers/usb/gadget/function/f_uac1_legacy.c
@@ -943,6 +943,7 @@ static void f_audio_free(struct usb_function *f)
 	struct f_audio *audio = func_to_audio(f);
 	struct f_uac1_legacy_opts *opts;
 
+	cancel_work_sync(&audio->playback_work);
 	gaudio_cleanup(&audio->card);
 	opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 	kfree(audio);
-- 
2.47.3