From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Wu , Takashi Iwai Subject: [PATCH 4.4 128/146] ALSA: hda - fix use-after-free after module unload Date: Mon, 25 Jul 2016 13:56:23 -0700 Message-Id: <20160725203526.638397924@linuxfoundation.org> In-Reply-To: <20160725203521.340401316@linuxfoundation.org> References: <20160725203521.340401316@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Wu commit ab58d8cc870ef3f0771c197700441936898d1f1d upstream. 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, initially noticed due to a general protection fault. Fixes: 246efa4a072f ("snd/hda: add runtime suspend/resume on optimus support (v4)") Signed-off-by: Peter Wu Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/pci/hda/hda_intel.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1256,8 +1256,10 @@ static int azx_free(struct azx *chip) if (use_vga_switcheroo(hda)) { if (chip->disabled && hda->probe_continued) snd_hda_unlock_devices(&chip->bus); - if (hda->vga_switcheroo_registered) + if (hda->vga_switcheroo_registered) { vga_switcheroo_unregister_client(chip->pci); + vga_switcheroo_fini_domain_pm_ops(chip->card->dev); + } } if (bus->chip_init) {