From 1699867f19f96466f9d3e30d62417548a05cf81d Mon Sep 17 00:00:00 2001 From: Peter Wu Date: Mon, 11 Jul 2016 19:51:06 +0200 Subject: [PATCH] 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 Signed-off-by: Takashi Iwai [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- sound/pci/hda/hda_intel.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 2f523b08f5762..8ff15d834ace3 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -950,8 +950,10 @@ static int azx_free(struct azx *chip) if (use_vga_switcheroo(chip)) { if (chip->disabled && chip->bus) snd_hda_unlock_devices(chip->bus); - if (chip->vga_switcheroo_registered) + if (chip->vga_switcheroo_registered) { vga_switcheroo_unregister_client(chip->pci); + vga_switcheroo_fini_domain_pm_ops(chip->card->dev); + } } if (chip->initialized) { -- 2.47.3