tree 49673707b98bf6aa4dd3a150583d8137bc32568f
parent 5a4ca9b3fa24f81298c13a27c03c6dd4087ca159
author Wang YanQing <udknight@gmail.com> 1367897253 +0800
committer Takashi Iwai <tiwai@suse.de> 1367904719 +0200

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>