dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted

When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.

dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:

	slab-use-after-free in dma_chan_put+0x3e6/0x4c0
	Read of size 8 by task insmod/6319
	Freed by task 6319:
	  kfree+0x225/0x470
	  dma_chan_put+0x395/0x4c0
	  dmaengine_put+0xf8/0x160

Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device.

Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct")
Suggested-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/sound/soc/codecs/chv3-codec.c b/sound/soc/codecs/chv3-codec.c
new file mode 100644
index 000000000..40020500b
--- /dev/null
+++ b/sound/soc/codecs/chv3-codec.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <sound/soc.h>
+
+static struct snd_soc_dai_driver chv3_codec_dai = {
+	.name = "chv3-codec-hifi",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 8,
+		.channels_max = 8,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE,
+	},
+};
+
+static const struct snd_soc_component_driver soc_component_dev_chv3_codec = {
+};
+
+static int chv3_codec_probe(struct platform_device *pdev)
+{
+	return devm_snd_soc_register_component(&pdev->dev,
+		&soc_component_dev_chv3_codec, &chv3_codec_dai, 1);
+}
+
+static const struct of_device_id chv3_codec_of_match[] = {
+	{ .compatible = "google,chv3-codec", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, chv3_codec_of_match);
+
+static struct platform_driver chv3_codec_platform_driver = {
+	.driver = {
+		.name = "chv3-codec",
+		.of_match_table = chv3_codec_of_match,
+	},
+	.probe = chv3_codec_probe,
+};
+module_platform_driver(chv3_codec_platform_driver);
+
+MODULE_DESCRIPTION("ASoC Chameleon v3 codec driver");
+MODULE_AUTHOR("Pawel Anikiel <pan@semihalf.com>");
+MODULE_LICENSE("GPL");