From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wang YanQing Subject: [PATCH]ALSA: HDA: Fix Oops caused by dereference NULL pointer Date: Tue, 7 May 2013 11:27:33 +0800 Message-ID: <20130507032733.GA29944@udknight> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: tiwai@suse.de Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, perex@perex.cz, david.henningsson@canonical.com List-Id: alsa-devel@alsa-project.org 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 --- 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