ALSA: hda - fix use-after-free after module unload

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 <peter@lekensteyn.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 03c34f65ceba931eafafc5efac0678d607a2bc45..873f5d1020ff7dea534ad2f9b69797268962c7d3 100644 (file)
--- 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) {