commit: 2195b063f6609e4c6268f291683902f25eaf9aa6 From: Wang YanQing <udknight@xxxxxxxxx> Date: Tue, 7 May 2013 11:27:33 +0800 Subject: ALSA: HDA: Fix Oops caused by dereference NULL pointer 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@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> --- sound/pci/hda/hda_codec.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 6f9b647..86674f6 100644 --- 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_bus *bus, u32 res, u32 res_ex) 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) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html