From 2195b063f6609e4c6268f291683902f25eaf9aa6 Mon Sep 17 00:00:00 2001 From: Wang YanQing Date: Tue, 7 May 2013 11:27:33 +0800 Subject: [PATCH] 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 Cc: Signed-off-by: Takashi Iwai --- 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 6f9b64700f6e..86674f67abd1 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) -- 2.34.1