This is a note to let you know that I've just added the patch titled

    ALSA: HDA: Fix Oops caused by dereference NULL pointer

to the 3.9-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     alsa-hda-fix-oops-caused-by-dereference-null-pointer.patch
and it can be found in the queue-3.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 2195b063f6609e4c6268f291683902f25eaf9aa6 Mon Sep 17 00:00:00 2001
From: Wang YanQing <[email protected]>
Date: Tue, 7 May 2013 11:27:33 +0800
Subject: ALSA: HDA: Fix Oops caused by dereference NULL pointer

From: Wang YanQing <[email protected]>

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 <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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
@@ -681,6 +681,9 @@ 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)


Patches currently in stable-queue which might be from [email protected] are

queue-3.9/alsa-hda-fix-oops-caused-by-dereference-null-pointer.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to