| From | Greg Kroah-Hartman <> | Subject | [ 05/50] ALSA: HDA: Fix Oops caused by dereference NULL pointer | Date | Fri, 17 May 2013 14:46:40 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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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 @@ -617,6 +617,9 @@ 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)
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