| From 2195b063f6609e4c6268f291683902f25eaf9aa6 Mon Sep 17 00:00:00 2001 |
| From: Wang YanQing <udknight@gmail.com> |
| Date: Tue, 7 May 2013 11:27:33 +0800 |
| Subject: ALSA: HDA: Fix Oops caused by dereference NULL pointer |
| |
| From: Wang YanQing <udknight@gmail.com> |
| |
| commit 2195b063f6609e4c6268f291683902f25eaf9aa6 upstream. |
| |
| The interrupt handler azx_interrupt will call azx_update_rirb, |
| which may call snd_hda_queue_unsol_event, snd_hda_queue_unsol_event |
| will dereference chip->bus pointer. |
| |
| The problem is we alloc chip->bus in azx_codec_create |
| which will be called after we enable IRQ and enable unsolicited |
| event in azx_probe. |
| |
| This will cause Oops due dereference NULL pointer. I meet it, good luck:) |
| |
| [Rearranged the NULL check before the tracepoint and added another |
| NULL check of bus->workq -- tiwai] |
| |
| Signed-off-by: Wang YanQing <udknight@gmail.com> |
| Signed-off-by: Takashi Iwai <tiwai@suse.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| sound/pci/hda/hda_codec.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/sound/pci/hda/hda_codec.c |
| +++ b/sound/pci/hda/hda_codec.c |
| @@ -681,6 +681,9 @@ int snd_hda_queue_unsol_event(struct hda |
| struct hda_bus_unsolicited *unsol; |
| unsigned int wp; |
| |
| + if (!bus || !bus->workq) |
| + return 0; |
| + |
| trace_hda_unsol_event(bus, res, res_ex); |
| unsol = bus->unsol; |
| if (!unsol) |
