On 11/14/2016 03:25 AM, Takashi Iwai wrote: > On Sat, 12 Nov 2016 00:34:38 +0100, > Shuah Khan wrote: >> >> Hi Takashi, >> >> I am seeing the following use-after-free error when I disconnect an >> USB speaker. I saw this on 4.9-rc4 and 4.8.7. There might be race >> condition between the disconnect and pcm close perhaps. > > Thanks, this looks like a new discovery. > Could you check whether the patch below works? > > > Takashi > > --- > diff --git a/sound/usb/card.c b/sound/usb/card.c > index 9e5276d6dda0..2ddc034673a8 100644 > --- a/sound/usb/card.c > +++ b/sound/usb/card.c > @@ -315,7 +315,8 @@ static int snd_usb_audio_free(struct snd_usb_audio *chip) > snd_usb_endpoint_free(ep); > > mutex_destroy(&chip->mutex); > - dev_set_drvdata(&chip->dev->dev, NULL); > + if (!atomic_read(&chip->shutdown)) > + dev_set_drvdata(&chip->dev->dev, NULL); > kfree(chip); > return 0; > } > Hi Takashi, The patch fixed the problem on 4.9-rc4. Didn't get a chance to test it on 4.8.7. thanks, -- Shuah _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
