From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Wu Subject: Re: [PATCH] snd/hda: fix use-after-free after module unload Date: Mon, 11 Jul 2016 19:32:05 +0200 Message-ID: <20160711173205.GA4475@al> References: <20160709143857.12044-1-peter@lekensteyn.nl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from lekensteyn.nl (lekensteyn.nl [178.21.112.251]) by alsa0.perex.cz (Postfix) with ESMTP id B052F26573C for ; Mon, 11 Jul 2016 19:32:25 +0200 (CEST) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On Mon, Jul 11, 2016 at 12:42:27PM +0200, Takashi Iwai wrote: > On Sat, 09 Jul 2016 16:38:57 +0200, > Peter Wu wrote: > > > > register_vga_switcheroo() sets the PM ops from the hda structure which > > is freed later in azx_free. Make sure that these ops are cleared. > > > > Caught by KASAN. > > > > Fixes: 246efa4a072f ("snd/hda: add runtime suspend/resume on optimus support (v4)") > > Signed-off-by: Peter Wu > > --- > > sound/pci/hda/hda_intel.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > > index 94089fc..a339066 100644 > > --- a/sound/pci/hda/hda_intel.c > > +++ b/sound/pci/hda/hda_intel.c > > @@ -1219,6 +1219,7 @@ static int azx_free(struct azx *chip) > > snd_hda_unlock_devices(&chip->bus); > > if (hda->vga_switcheroo_registered) > > vga_switcheroo_unregister_client(chip->pci); > > + vga_switcheroo_fini_domain_pm_ops(chip->card->dev); > > The domain pm ops is set only when hda->vga_switcheroo_registered flag > is set. So the call should be in the previous if block. Yes that would be cleaner, will do that. > Also, the indentation looks wrong. Please use the correct > indentation. Noticed too late that the editor config was wrong on the testing machine. > Could you resubmit with these fixes? I will, thanks for the feedback! -- Kind regards, Peter Wu https://lekensteyn.nl