Messages in this thread | | | Date | Tue, 07 May 2013 07:34:59 +0200 | From | Takashi Iwai <> | Subject | Re: [PATCH]ALSA: HDA: Fix Oops caused by dereference NULL pointer |
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At Tue, 7 May 2013 11:27:33 +0800, Wang YanQing wrote: > > 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:) > > Signed-off-by: Wang YanQing <udknight@gmail.com>
Thanks, applied with a slight fix (put before the tracepoint so that it won't give more NULL dereference, and also put another NULL check of bus->workq as done in hda_intel.c.)
Takashi
> --- > 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 622f726..9c76752 100644 > --- a/sound/pci/hda/hda_codec.c > +++ b/sound/pci/hda/hda_codec.c > @@ -618,6 +618,9 @@ int snd_hda_queue_unsol_event(struct hda_bus *bus, u32 res, u32 res_ex) > unsigned int wp; > > trace_hda_unsol_event(bus, res, res_ex); > + if (!bus) > + return 0; > + > unsol = bus->unsol; > if (!unsol) > return 0; > -- > 1.7.12.4.dirty >
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