Patch "ALSA: hda: fix possible NULL dereference" has been added to the 4.1-stable tree

Patch "ALSA: hda: fix possible NULL dereference" has been added to the 4.1-stable tree

[gregkh]

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

    ALSA: hda: fix possible NULL dereference

to the 4.1-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-possible-null-dereference.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From c7e69ae6b4ff49edf50180c0a32f3dd9d7967e31 Mon Sep 17 00:00:00 2001
From: Markus Osterhoff <linux-kernel@k-raum.org>
Date: Mon, 24 Aug 2015 14:11:39 +0200
Subject: ALSA: hda: fix possible NULL dereference

From: Markus Osterhoff <linux-kernel@k-raum.org>

commit c7e69ae6b4ff49edf50180c0a32f3dd9d7967e31 upstream.

After a for-loop was replaced by list_for_each_entry, see
Commit bbbc7e8502c9 ("ALSA: hda - Allocate hda_pcm objects dynamically"),
Commit 751e2216899c ("ALSA: hda: fix possible null dereference"),
a possible NULL pointer dereference has been introduced; this patch adds
the NULL check on pcm->pcm, while leaving a potentially superfluous
check on pcm itself untouched.

Signed-off-by: Markus Osterhoff <linux-kernel@k-raum.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 sound/pci/hda/hda_codec.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3259,7 +3259,7 @@ static int add_std_chmaps(struct hda_cod
 			struct snd_pcm_chmap *chmap;
 			const struct snd_pcm_chmap_elem *elem;
 
-			if (!pcm || pcm->own_chmap ||
+			if (!pcm || !pcm->pcm || pcm->own_chmap ||
 			    !hinfo->substreams)
 				continue;
 			elem = hinfo->chmap ? hinfo->chmap : snd_pcm_std_chmaps;


Patches currently in stable-queue which might be from linux-kernel@k-raum.org are

queue-4.1/alsa-hda-fix-possible-null-dereference.patch