From: Wang YanQing <udknight@gmail.com>
Date: Tue, 7 May 2013 03:27:33 +0000 (+0800)
Subject: ALSA: HDA: Fix Oops caused by dereference NULL pointer
X-Git-Tag: v3.10-rc1~14^2~3
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2195b063f6609e4c6268f291683902f25eaf9aa6;p=pandora-kernel.git

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@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

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