At Tue, 16 Oct 2012 18:01:13 +0200, Matthieu CASTET wrote: > > Takashi Iwai a écrit : > > At Mon, 15 Oct 2012 19:41:40 +0200, > > Matthieu CASTET wrote: > >> Hi Takashi, > >> > >> But I believe I found other races in the alsa char device handling. With the > >> attached patch, if you disconnect the usb audio device between "msleep o" and > >> "msleep o+", you will free the card resource (snd_card_do_free) and then use it [1]. > >> > >> I did in in snd_ctl_open, but the same thing could be done in snd_pcm_open, ... > > > > OK, we'd need a generic open/close protection. > > For PCM, there is already a fix in my last patchset, so it should > > work, but for other devices, the paths are still uncovered. > > > I don't think it will work for pcm : the begin of snd_pcm_open is not protected > by any lock even with your patch > In snd_open we release sound_mutex before calling file->f_op->open. > > The snd_lookup_minor_data and snd_card_file_add should be protected by a lock. > Attached a patch (pcm.crash) that help to trigger [1]. Check out my latest patches in topic/usb-disconnect-fix branch. It's been fixed there. Takashi -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
