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, 56 insertions, 0 deletions

diff --git a/include/sound/sof/pm.h b/include/sound/sof/pm.h
new file mode 100644
index 000000000..df55bfe58
--- /dev/null
+++ b/include/sound/sof/pm.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#ifndef __INCLUDE_SOUND_SOF_PM_H__
+#define __INCLUDE_SOUND_SOF_PM_H__
+
+#include <sound/sof/header.h>
+
+/*
+ * PM
+ */
+
+/* PM context element */
+struct sof_ipc_pm_ctx_elem {
+	struct sof_ipc_hdr hdr;
+	uint32_t type;
+	uint32_t size;
+	uint64_t addr;
+}  __packed;
+
+/*
+ * PM context - SOF_IPC_PM_CTX_SAVE, SOF_IPC_PM_CTX_RESTORE,
+ * SOF_IPC_PM_CTX_SIZE
+ */
+struct sof_ipc_pm_ctx {
+	struct sof_ipc_cmd_hdr hdr;
+	struct sof_ipc_host_buffer buffer;
+	uint32_t num_elems;
+	uint32_t size;
+
+	/* reserved for future use */
+	uint32_t reserved[8];
+
+	struct sof_ipc_pm_ctx_elem elems[];
+} __packed;
+
+/* enable or disable cores - SOF_IPC_PM_CORE_ENABLE */
+struct sof_ipc_pm_core_config {
+	struct sof_ipc_cmd_hdr hdr;
+	uint32_t enable_mask;
+} __packed;
+
+struct sof_ipc_pm_gate {
+	struct sof_ipc_cmd_hdr hdr;
+	uint32_t flags;	/* platform specific */
+
+	/* reserved for future use */
+	uint32_t reserved[5];
+} __packed;
+
+#endif