linux-kernel - bugs in "ASoC: core - Optimise and refactor pcm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 14 Dec 2011 12:43:50 +0000
From:	James Hogan <james.hogan@...tec.com>
To:	Liam Girdwood <lrg@...com>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.de>,
	<alsa-devel@...a-project.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Neil <neil.jones@...tec.com>
Subject: bugs in "ASoC: core - Optimise and refactor pcm_new() to pass only
 rtd"?

Hi,

I've bisected a problem with an out of tree set of asoc drivers down to commit
552d1ef6b5a98d7b95959d5b139071e3c90cebf1 ("ASoC: core - Optimise and refactor
pcm_new() to pass only rtd"). By the looks of it this change was intended not 
to change the workings of the code, however the dai parameter of pcm_new used
to be passed codec_dai in soc_new_pcm() (initialised from rtd->codec_dai), but
each driver now sets it's dai to rtd->cpu_dai instead. This seems to make the
driver check the wrong dai's driver->capture.channels_min in the pcm_new
callback, which makes it dereference
pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream in the driver's
preallocate_dma_buffer() function which can be NULL. Is this a bug (in every
pcm asoc driver) that just happens not to have been noticed, or have I
misunderstood it?

Relevant snippets of the original patch below.

Thanks
James

diff --git a/sound/soc/samsung/dma.c b/sound/soc/samsung/dma.c
index 5cb3b88..9465588 100644
--- a/sound/soc/samsung/dma.c
+++ b/sound/soc/samsung/dma.c
@@ -425,9 +425,11 @@ static void dma_free_dma_buffers(struct snd_pcm *pcm)

 static u64 dma_mask = DMA_BIT_MASK(32);

-static int dma_new(struct snd_card *card,
-	struct snd_soc_dai *dai, struct snd_pcm *pcm)
+static int dma_new(struct snd_soc_pcm_runtime *rtd)
 {
+	struct snd_card *card = rtd->card->snd_card;
+	struct snd_soc_dai *dai = rtd->cpu_dai;
+	struct snd_pcm *pcm = rtd->pcm;
 	int ret = 0;

 	pr_debug("Entered %s\n", __func__);

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index c53f5d5..29bf9fb 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -2143,8 +2143,7 @@ static int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &soc_pcm_ops);

 	if (platform->driver->pcm_new) {
-		ret = platform->driver->pcm_new(rtd->card->snd_card,
-						codec_dai, pcm);
+		ret = platform->driver->pcm_new(rtd);
 		if (ret < 0) {
 			pr_err("asoc: platform pcm constructor failed\n");
 			return ret;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/